US7239798B2 - Apparatus and method using compressed codes for scheduling broadcast information recording - Google Patents

Abstract

Digital compressed codes, associated with advertisements enable a user to selectively record additional information, which would be broadcast on a television channel at a later time. The advertisement could be print advertisement or broadcast advertisement on television or radio. The user enters the digital code (I code) associated with an advertisement into a unit with a decoding means which automatically converts the code into CTL (channel, time and length). The unit within a twenty four hour period activates a VCR to record information on the television channel at the right time for the proper length of time. The decoded channel, time and length information can be communicated directly to a VCR and used by the VCR directly to automatically activate the VCR to record a given television information broadcast corresponding to the communicated channel, time and length. Alternately, the channel, time and length information can be decoded directly in a remote control unit and only start record, stop record and channel selection commands sent to the VCR at the appropriate times. Algorithms for decoding the I codes can be a function of time to ensure security of the decoding method. A method is included for use of the I codes with cable channels.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent Ser. No. 10/272,232, filed Oct. 15, 2002, and to be issued on Dec. 23, 2003, as U.S. Pat. No. 6,668,133, which is a continuation of U.S. patent application Ser. No. 09/374,137 filed Aug. 10, 1999 now U.S. Pat. No. 6,466,734, which is a divisional of U.S. patent application Ser. No. 08/848,533 filed on Apr. 28, 1997, issued as U.S. Pat. No. 5,974,222, which is a continuation of U.S. patent application Ser. No. 08/327,140 filed on Oct. 20, 1994 (abandoned), which is a continuation of U.S. patent application Ser. No. 07/806,152 filed on Dec. 11, 1991 (abandoned), which is continuation in part of U.S. patent application Ser. No. 07/676,934 filed Mar. 27, 1991, issued as U.S. patent application Ser. No. 5,335,079, which is a continuation in part of U.S. patent application Ser. No. 07/371,054 filed Jun. 26, 1989 (abandoned), which itself is a continuation in part of Ser. No. 07/289,369, filed Dec. 23, 1988 (abandoned), each of which is incorporated by reference as if set forth herein in full.

BACKGROUND OF THE INVENTION

This invention relates generally to video cassette recorder systems and particularly to the timer preprogramming feature of video cassette recorders (VCRs) and to an apparatus and method for using encoded information to shorten the time required to perform timer preprogramming and also an apparatus and method for enabling a user to selectively record, for later viewing, detailed information that is associated with an earlier publication or broadcast of an advertisement.

The video cassette recorder (VCR) has a number of uses, including playing back of tapes filmed by a video camera, playing back of pre-recorded tapes, and recording and playing back of broadcast and cable television programs.

To record a television program in advance of viewing it, a two-step process is often used: (1) obtain the correct channel, date, time and length (CDTL) information from a television program guide, and (2) program this CDTL information into the VCR. Depending on the model, year and type of the VCR, the CDTL information can be programmed in various ways including: (i) pushing an appropriate sequence of keys in the console according to instructions contained in the user's manual, (ii) pushing an appropriate sequence of keys in a remote hand-held control unit according to instructions contained in the user's manual (remote programming), and (iii) executing a series of keystrokes in the remote hand-held control unit in response to a menu displayed on the television screen (on-screen programming). Other techniques for timer preprogramming have been suggested including: (iv) reading in certain bar-code information using a light pen (light pen programming), and (v) entering instructions through a computer or telephone modem. These various methods differ only in the physical means of specifying the information while the contents, being CDTL and certain power/clock/timer on-off commands are generally common although the detailed protocol can vary with different model VCRs. Methods (i) and (ii) described above can require up to 100 keystrokes, which has inhibited the free use of the timer preprogramming feature of VCRs. To alleviate this, new VCR models have included an “On-Screen Programming” feature, which permits remote input of CDTL information in response to a menu displayed on the television screen. Generally on screen programming of CDTL information requires an average of about 18 keystrokes, which is less than some of the prior methods but still rather substantial. Some of the other techniques such as (iv) above, require the use of special equipment such as a bar code reader.

In general the present state of the art suffers from a number of drawbacks. First, the procedure for setting the VCR to record in advance can be quite complex and confusing and difficult to learn; in fact, because of this many VCR owners shun using the timer preprogramming record feature. Second, the transcription of the CDTL information to the VCR is hardly ever error-free; in fact, many users of VCR's timer preprogramming features express concern over the high incidence of programming errors. Third, even for experienced users, the process of entering a lengthy sequence of information on the channel, date, time and length of desired program can become tedious. Fourth, techniques such as reading in bar-code information or using a computer require special equipment. These drawbacks have created a serious impedance in the use of a VCR as a recording device for television programs. The effect is that time shifting of programs has not become as popular as it once was thought it would be. Accordingly, there is a need in the art for a simpler system for effecting VCR timer preprogramming which will enable a user to take advantage of the recording feature of a VCR more fully and freely.

The prior art in the area of enabling a user to selectively record for later viewing, detailed information associated with an advertisement is the familiar advertisement by a network during a television channel commercial break that there will be “news at 11” or that there will be an “interview with the winning coach at 9”. A viewer watching the channel that sees/hears this announcement could preprogram his VCR to record the “news” or “interview” at the appropriate time. Thus, the concept of having a cue broadcast simultaneously with a advertisement that alerts a user that supplemental information regarding the advertisement will be broadcast at a later time can be implemented easily with standard apparatus such as a television and a VCR and is not new to the state of the art. The user could also be informed of an “interview with the winning coach” through print advertisement, which would indicate the channel time and date of the interview. When the user is informed either through a broadcast or a printed advertisement that a winning team's coach will be interviewed later that day, the viewer uses his standard remote controller to program his VCR to automatically record this later program. The VCR stores the schedule information from the controller and, via its display panel, provides acknowledgment to the user of his programming commands.

U.S. Pat. No. 4,977,455 for a System and Process for VCR Scheduling discloses a television broadcast system in which a cue is broadcast and displayed simultaneously with a primary program. The cue alerts a user that supplemental information regarding the primary program will be broadcast at a later time. If the user responds to the cue via a remote controller, then data embedded in the primary program broadcast during the video blanking interval segment of the video signal, but not visible to the viewer, will be automatically stored and interpreted by a microprocessor and used to control a VCR to record the supplemental broadcast at the later time. Young does not contemplate the use of printed media at all and requires that a special unit be associated with the television receiver to store and interpret the data embedded in the primary program broadcast, and also to respond to the user cue, for the system to work at all, even for television advertisements, as shown inelements 4, 5, 9, 10, and 15 of FIG. 1, of U.S. Pat. No. 4,977,455.

SUMMARY OF THE INVENTION

A principal object of the invention is to provide an improved system for the selection and entering of channel, date, time and length (CDTL) information required for timer preprogramming of a VCR which is substantially simpler, faster and less error-prone than present techniques. Another principal object of the invention is to provide an improved apparatus and method for enabling a user to selectively record, for later viewing, detailed information that is associated with an earlier publication or broadcast of an advertisement.

In accordance with the invention, to program the timer preprogramming feature of a video system, there is an apparatus and method for using encoded video recorder/player timer preprogramming information. The purpose is to significantly reduce the number of keystrokes required to set up the timer preprogramming feature on a VCR. In accordance with this invention it is only necessary for the user to enter a code with 1 to 7 digits or more into the VCR. This can be done either remotely or locally at the VCR. Built into either the remote controller or the VCR is a decoding means which automatically converts the code into the proper CDTL programming information and activates the VCR to record a given television program with the corresponding channel, date, time and length. Generally multiple codes can be entered at one time for multiple program selections. The code can be printed in a television program guide in advance and selected for use with a VCR or remote controller with the decoding means.

Another principal object of the invention is to enable a user to selectively record information designated by a digital code, which would be associated with an advertisement. The advertisement could be print advertisement or a broadcast advertisement on television or radio. The additional information could be broadcast on a television channel early in the morning, for example, between midnight and six o'clock in the morning, when the broadcast rates are low and it is economical to broadcast detailed information or advertisements of many items, especially expensive ones, such as automobiles and real estate. In accordance with this invention it is only necessary for the user to enter a digital compressed code associated with an advertisement into a unit with a decoding means which automatically converts the code into CTL (channel, time and length). The unit activates a VCR to record information on the television channel starting at the right time and recording for the proper length of time. The information will be recorded within the next twenty four hours so it is not necessary to decode any date. The user can then view this information at his/her leisure.

Other objects and many of the attendant features of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed descriptions and considered in connection with the accompanying drawings in which like reference symbols designate like parts throughout the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic showing apparatus according to this invention with the code decoder means embedded in the video cassette recorder;

FIG. 2 is a schematic of the VCR embedded processors for command control and code decoding;

FIG. 3 is a schematic showing a preferred embodiment according to this invention with the code decoder means embedded in a remote controller;

FIG. 4 is a schematic of the processor embedded in the remote controller;

FIG. 5 is a schematic of a universal remote controller with the code decoder means embedded in the universal remote controller;

FIG. 6 is a flow graph of the G-code decoding technique;

FIG. 7 is a flow graph of the G-code encoding technique;

FIG. 8 is an illustration of part of a television calendar according to this invention;

FIG. 9 is a flowchart for decoding for cable channels;

FIG. 10 is a flowchart for encoding for cable channels;

FIG. 11 is a flow graph of the G-code decoding for cable channels including conversion from assigned cable channel number to local cable carrier channel number;

FIG. 12 is a means for decoding including a stack memory;

FIG. 13 is a flowchart for program entry into stack memory;

FIG. 14 is an operation flowchart for sending programs from remote control to main unit VCR;

FIG. 15 is a perspective view of an apparatus for using compressed codes for recorder prepregramming according to a preferred embodiment of the invention;

FIG. 16 is a front view of the apparatus ofFIG. 15 showing a forward facing light emitting diode;

FIG. 17 is a perspective view of the apparatus ofFIG. 15 placed in a mounting stand;

FIG. 18 is a detail of the LCD display of the apparatus ofFIG. 15;

FIG. 19 is a perspective view showing a manner of placing the apparatus ofFIG. 15 relative to a cable box and a VCR;

FIG. 20 is a perspective view showing a manner of placing the mounting stand with the apparatus ofFIG. 15 mounted thereon near a cable box and VCR;

FIG. 21 is a schematic showing apparatus for using compressed codes for recorder prepregramming according to a preferred embodiment of the invention;

FIG. 22 is a detailed schematic showing a preferred embodiment of apparatus implementing the schematic ofFIG. 21

FIG. 23 is a flow graph for program entry into the apparatus ofFIG. 15;

FIG. 24 is a flow graph for review and program cancellation of programs entered into the apparatus ofFIG. 15;

FIG. 25 is a flow graph for executing recorder prepregramming using compressed codes according to a preferred embodiment of the invention;

FIG. 26 is a flow graph for encoding program channel, date, time and length information into decimal compressed codes;

FIG. 27 is a flow graph for decoding decimal compressed codes into program channel, date, time and length information;

FIG. 28 is an embodiment of an assigned channel number/local channel number table;

FIGS. 29aand29bare examples of a printed advertisement and a television broadcast advertisement showing the use of a decimal code for information (I code);

FIG. 30 is a flow graph for entry of an I code into the apparatus ofFIG. 15;

FIG. 31 is a flow graph for encoding channel, time and length (CTL) into an I code;

FIG. 32 is a flow graph for decoding an I code channel, time and length (CTL); and

FIG. 33 illustrates the relationship of time spans and validity period codes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, and more particularly, toFIG. 1, there is shown an apparatus for using encoded video recorder/playertimer preprogramming information10 according to this invention. The primary components include aremote controller12 and a video cassette recorder/player with G-code decoder14, which can be controlled byremote controller12 via acommand signal16. Theremote controller12 can have a number of keys, which includenumerical keys20, G-code switch22,function keys24,program key26 andpower key27. There are means in theremote controller12 that interprets each key as it is pressed and sends theproper command signal16 to the VCR via an infra-redlight emitting diode28. Except for the G-code switch22 on theremote controller12 inFIG. 1, theremote controller12 is essentially the same as any other remote controller in function. The G-code switch22 is provided just to allow the user to lock theremote controller12 in the G-code mode while using a G-code, which is the name given to the compressed code which is the encoded CDTL information, to perform timer preprogramming.

A G-code consists of 1 to 7 digits, although more could be used, and is associated with a particular program. A user would lookup the G-code in a program guide and just enter the G-code on theremote controller12, instead of the present state of the art, which requires that the user enter the actual channel, date, time and length (CDTL) commands.

In order to understand the advantages of using a G-code, it is helpful to describe the best of the current state of the art, which is “on screen programming” with direct numerial entry. This technique involves about 18 keystrokes and the user has to keep switching his view back and forth between the TV screen and the remote controller while entering the CDTL information. This situation may be akin to a user having to dial an 18 digit telephone number while reading it from a phone book. The number of keys involved and the switching back and forth of the eye tend to induce errors. A typical keying sequence for timer recording using on-screen CDTL programming is as follows:

• • PROG 2 1 15 07 30 2 08 00 2 04 PROG

The first program (PROG)key26 enters the programming mode. Then a sequence of numericals key20 are pushed. The 2 means it is timer recording rather than time setting. The 1 means the user is now entering the settings forprogram 1. The 15 is the date. The 07 is starting hour. The 30 is a starting minute. The 2 means pm. The next sequence 08 00 2 is the stopping time. The 04 is channel number. Finally, the PROG is hit again to exit the program mode.

By contrast, this command could have been “coded” and entered in a typical G-code sequence as follows: PROG 1138 PROG. To distinguish that the command is a coded G-code, the G-code switch22 should be turned to the “ON” position. Instead of having a switch, a separate key “G” can be used. The G-code programming keystroke sequence would then be: G 1138 PROG.

The use of a G-code does not preclude “on-screen” confirmation of the program information that has been entered. When the keystrokes “PROG 1138 PROG” are entered with the G-code switch in the “ON” position, the G-code would be decoded and the television could display the following message:

PROGRAM	DATE	START TIME	STOP TIME	CHANNEL
1138	15	7:30 PM	8:00PM	4

In order for the G-code to be useful it must be decoded and apparatus for that purpose must be provided. Referring toFIG. 1, a video cassette recorder/player with G-code decoder14 is provided to be used in conjunction withremote controller12. Thecommand signal16 sent from theremote controller12 is sensed by thephotodiode32 and converted to electrical signals bycommand signal receiver30. The electrical signals are sent to acommand controller36, which interprets the commands and determines how to respond to the commands. As shown inFIG. 1, it is also possible for thecommand controller36 to receive commands from the manual controls34 that are normally built into a VCR. If thecommand controller36 determines that a G-code was received then the G-code will be sent to the G-code decoder38 for decoding. The G-code decoder38 converts the C-code into CDTL information, which is used by thecommand controller36 to set the time/channel programming40. Built into the VCR is aclock42. This is normally provided in a VCR and is used to keep track of the date and time. Theclock42 is used primarily by the time/channel programming40 and the G-code decoder38 functions. The time/channel programming40 function is set up with CDTL information by thecommand controller36. When the proper date and time is read fromclock42, then the time/channel programming40 function turns the record/playback44 function “ON” to record. At the same time thetuner46 is tuned to the proper channel in thetelevision signal18. Later the user can command the record/playback44 function to a playback mode to watch the program via thetelevision monitor48.

An alternate way to control the recorder is to have thecommand controller36 keep all the CDTL information instead of sending it to the time/channel programming40. The command controller would also keep track of the time by periodically readingclock42. The command controller would then send commands to the time/channel programming40 to turn on and off the recorder and totuner46 to cause it to tune to the right channel at the right time according to the CDTL information.

Theclock42 is also an input to G-code decoder38, which allows the G-code decoding to be a function of the clock, which lends a measure of security to the decoding technique and makes it harder to copy. Of course this requires that the encoding technique must also be a function of the clock.

A possible realization of thecommand controller36 and the G-code decoder38 is shown inFIG. 2. Thecommand controller36 function can be realized with amicroprocessor50, arandom access memory52 and a read onlymemory54, which is used for program storage. The input/output56 function is adapted to receive commands from thecommand signal receiver30, the manual controls34 and theclock42, and to output signals to adisplay35, theclock42, and the time/channel programming40 function. If themicroprocessor50 interprets that a G-code has been received, then the G-code is sent tomicrocontroller60 for decoding. Themicrocontroller60 has an embeddedrandom access memory62 and an embedded read only memory64 for program and table storage. Theclock42 can be read by bothmicroprocessor50 andmicrocontroller60.

An alternative to havingmicrocontroller60 perform the G-code decoding is to build the G-code decoding directly into the program stored in read onlymemory54. This would eliminate the need formicrocontroller60. Of course, other hardware to perform the G-code decoding can also be used. The choice of which implementation to use is primarily an economic one.

The blocks inFIGS. 1 and 2 are well known in the prior art and are present in the following patents: Fields, U.S. Pat. No. 4,481,412; Scholz, U.S. Pat. No. 4,519,003; and Brugliera, U.S. Pat. No. 4,631,601. For example,clock42 is analogous toelement 7 in Scholz and element 17 in Brugliera. Other analogous elements are:command signal receiver30 andScholz 14 andBrugliera 12;tuner46 andScholz 6 andBrugliera 10; time/channel programming40 andScholz 8, 11 andBrugliera 16; record &playback44 andScholz 1, 2, 4;command controller36 andScholz 11, 10 andBrugliera 12;microprocessor50 andFields 27;RAM62 andFields 34;ROM54 and Fields 33; manual controls34 andScholz 15, 16; andremote controller12 andScholz 26 andBrugliera 18.

FIG. 3 illustrates an alternate preferred embodiment of this invention. InFIG. 3 a remote controller with embedded G-code decoder80 is provided. The remote controller with embedded G-code decoder80 is very similar toremote controller12, except for the addition of the G-code decoder82. Note that it is also possible in any remote controller to provide adisplay84. The remote controller with embedded G-code decoder80 would be used in conjunction with a normal video cassette recorder/player70, which would not be required to have an embedded G-code decoder. The numerals for the subelements of video cassette recorder/player70 are the same as described above for the video cassette recorder/player with G-code decoder14 and have the same function, except for the absence of G-code decoder38. This preferred embodiment has the advantage that it can be used in conjunction with VCRs that are presently being used. These do not have a G-code decoding capability. Replacing their remote controllers with ones that have this capability built-in can vastly improve the capability to do timer preprogramming for a modest cost.

FIG. 4 illustrates a possible realization of the G-code decoder82 built into the remote controller with embedded G-code decoder80. Amicroprocessor60 can be used as before to decode the G-code, as well as interface with thedisplay84, aclock85, the keypad88 and thelight emitting diode28. Alternately, other hardware implementations can be used to perform the G-code decoding. Theclock85 is provided in the remote controller80 so that the G-code decoder82 can be made to have theclock85 as one of its inputs. This allows the G-code decoding to be a function of theclock85, which lends a measure of security to the decoding technique and makes it harder to copy.

The remote controller with embedded G-code decoder as described above would send channel, date, time and length information to the video cassette recorder/player70, which would use the CDTL information for tuning into the correct channel and starting and stopping the recording function. The remote controller may have to be unique for each different video cassette recorder/player, because each brand or model may have different infrared pulses for each type of information sent such as the channel number keys and start record and stop record keys. The particular infrared pulses used for each key type can be called the vocabulary of the particular remote controller. Each model may also have a different protocol or order of keys that need to be pushed to accomplish a function such as timer preprogramming. The protocol or order of keys to accomplish a function can be called sentence structure. If there is a unique remote controller built for each model type, then the proper vocabulary and sentence structure can be built directly into the remote controller.

An alternate to having the remote controller with embedded G-code decoder send channel, date, time and length information to the video cassette recorder/player70, is to have the remote controller with embedded G-code decoder perform more operations to simplify the interfacing problem with existing video cassette recorder/players. In particular, if the remote controller not only performs the G-code decoding to CDTL, but also keeps track of time viaclock85, then it is possible for the remote controller to send just channel, start record and stop commands to the video cassette recorder/player. The channel, start and stop are usually basic one or two key commands, which means there is no complicated protocol or sentence structure involved. Thus, to communicate with a diverse set of video cassette recorder/player models it is only necessary to have memory within the remote controller, such as ROM64 ofFIG. 4, for storing the protocol for all the models or at least a large subset. The G-code would be entered on the remote controller as before and decoded into channel, date, time and length information, which would be stored in the remote controller. Viaclock85, the time would be checked and when the correct time arrives the remote controller would automatically send out commands to the VCR unit for tuning to the correct channel and for starting and stopping the recording. It is estimated that only two (2) bytes per key for about 15 keys need to be stored for the vocabulary for each video cassette recorder/player model. Thus, to cover 50 models would only require about 30*50=1500 bytes of memory in the remote controller. It would be necessary to position the remote controller properly with respect to the VCR unit so that the infrared signals sent by the remote controller are received by the unit.

Another preferred embodiment is to provide a universalremote controller90 with an embedded G-code decoder. Universal remote controllers provide the capability to mimic a number of different remote controllers. This reduces the number of remote controllers that a user needs to have. This is accomplished by having a learnfunction key94 function on the universal remote controller, as shown inFIG. 5. If thelearn function key94 is pushed in conjunction with another key, the unit will enter into the learn mode. Incoming infra-red (IR) pulses from the remote controller to be learned are detected by the infra-red photodiode96, filtered and wave-shaped into recognizable bit patterns before being recorded by a microcontroller into a battery-backed static RAM as the particular IR pulse pattern for that particular key. This is done for all the individual keys.

An example of more complex learning is the following. If thelearn function key94 in conjunction with theprogram key26 are pushed when the G-code switch is “ON”, the unit will recognize that it is about to record the keying sequence of a predetermined specific example of timer preprogramming of the particular VCR involved. The user will then enter the keying sequence from which the universalremote controller90 can then deduce and record the protocol of the timer preprogramming sequence. This is necessary because different VCRs may have different timer preprogramming command formats.

If keys are pushed without thelearn function key94 involved, the microcontroller should recognize it is now in the execute mode. If the key is one of the direct command keys, the microcontroller will read back from its static RAM the stored pulse sequence and send out command words through the output parallel I/O to pulse the outputlight emitting diode28. If the key is the PROG key and the G-code switch is “OFF”, then the microcontroller should recognize the following keys up to the next PROG key as a timer preprogramming CDTL command and send it out through thelight emitting diode28. If the G-code switch22 is set to “ON” and theprogram key26 is pushed, the microcontroller should recognize the following keys up to the next PROG key as a G-code command for timer preprogramming. It will decode the G-code into channel, date, start time and length (CDTL) and the microcontroller will then look up in it's static RAM “dictionary” the associated infra-red pulse patterns and concatenate them together before sending them off through the output parallel I/O to pulse thelight emitting diode28 to send the whole message in one continuous stream to the VCR.

FIG. 4 illustrates a possible realization of the G-code decoder92 that could be built into the universal remote controller with embedded G-code decoder90. Amicrocontroller60 can be used as before to decode the G-code, as well as for interfacing with the input/output functions including thephotodiode96. Alternately, the G-code decoding can be performed with other hardware implementations.

The universal remote controller can also be used in another manner to simplify the interfacing problem with existing video cassette recorder/players. In particular, if the universal remote controller performs not only the G-code decoding to CDTL, but also keeps track of time viaclock85 inFIG. 4, then it is possible for the universal remote controller to send just channel, start record and stop commands to the video cassette recorder/player, which as explained before, are usually basic one key commands, which means there is no complicated protocol or sentence structure involved. Thus, to communicate with a diverse set of video cassette recorder/player models it is only necessary for the universal remote controller to “learn” each key of the remote controller it is replacing. The G-code would be entered on the universal remote controller as before and decoded into channel, date, time and length information, which would be stored in the universal remote controller. Viaclock85, the time would be checked and when the correct time arrives the universal remote controller would automatically send out commands to the VCR unit for tuning to the correct channel and for starting and stopping the recording. It would be necessary to position the universal remote controller properly with respect to the VCR unit so that the signals sent by the universal remote are received by the VCR unit.

There are a number of ways that the G-code decoding can be performed. The most obvious way is to just have a large look up table. The G-code would be the index. Unfortunately, this would be very inefficient and result in a very expensive decoder due to the memory involved. The total storage involved is a function of the number of total combinations. If we allow for 128 channels, 31 days in a month, 48 on the hour and on the half hour start times in a twenty four hour day, and 16 length selections in half hour increments, then the total number of combinations is 128×31×48×16=3,047,424. This number of combinations can be represented by a 7 digit number. The address to the table would be the 7 digit number. In the worse case, this requires a lookup table that has about 4,000,000 rows by 15 to 16 digital columns, depending on the particular protocol. These digital columns would correspond to the CDTL information required for “on screen programming”. Each digit could be represented by a 4 bit binary number. Thus, the total storage number of bits required for the lookup table would be about 4,000,000×16×4=256,000,000. The present state of the art has about 1 million bits per chip. Thus, G-code decoding using a straightforward table lookup would require a prohibitively expensive number of chips.

Fortunately, there are much more clever ways of performing the G-code decoding.FIG. 6 is a flow diagram of a preferred G-code decoding technique. To understand G-code decoding, it is easiest to first explain the G-code encoding technique, for whichFIG. 7 is the flow chart. Then the G-code decoding technique, which is the reverse of the G-code encoding will be explained.

The encoding of the G-codes can be done on any computer and is done prior to preparation of any program guide that would include G-codes. For each program that will be printed in the guide, a channel, date, time and length (CDTL)code144 is entered in step142. Step146 separately reads the priority for the channel, date, time and length in thepriority vector storage122, which can be stored in read only memory64. Thepriority vector storage122 contains four tables: a priority vector C table124, a priority vector D table126, a priority vector T table128 and a priority vector L table130.

The channel priority table is ordered so that the most frequently used channels have a low priority number. An example of the data that is in priority vector C table124 follows.

	channel

	4	7	2	3	5	6	11	13 . . .

priority	0	1	2	3	4	5	6	7 . . .

Generally the dates of a month all have an equal priority, so the low number days in a month and the low number priorities would correspond in the priority vector D table as in the following example.

	date

	1	2	3	4	5	6	7	8	9	10 . . .

priority	0	1	2	3	4	5	6	7	8	9 . . .

The priority of the start times would be arranged so that prime time would have a low priority number and programs in the dead of the night would have a high priority number. For example, the priority vector T table would contain:

	time

	6:30 pm	7:00 pm	8:00 pm	7:30 pm . . .

	priority	0	1	2	3 . . .

An example of the data that is in the priority vector L table130 is the following:

	length of program (hours)

	0.5	1.0	2.0	1.5	3.0 . . .

	priority	0	1	2	3	4 . . .

Suppose the channel date time length (CDTL)144 data is 5 10 19.00 1.5, which meanschannel 5, 10th day of the month, 7:00 PM, and 1.5 hours in length, then for the above example the C_p, D_p, T_p, L_pdata148, which are the result of looking up the priorities for channel, date, time and length in priority tables124,126,128 and130 ofFIG. 7, would be 4 9 1 3. Step150 converts C_p, D_p, T_p, L_pdata to binary numbers. The number of binary bits in each conversion is determined by the number of combinations involved. Seven bits for C_p, which can be denoted as C₇C₆C₅C₄C₃C₂C₁, would provide for 128 channels. Five bits for D_p, which can be denoted as D₅D₄D₃D₂D₁, would provide for 31 days in a month. Six bits for T_p, which can be denoted as T₆T₅T₄T₃T₂T₁, would provide for 48 start times on each half hour of a twenty four hour day. Four bits for length, which can be denoted as L₄L₃L₂L₁, would provide for a program length of up to 8 hours in half hour steps. Together there are 7+5+6+4=22 bits of information, which correspond to 2**22=4,194,304 combinations.

The next step is to usebit hierarchy key120, which can be stored in read only memory64 to reorder the 22 bits. Thebit hierarchy key120 can be any ordering of the 22 bits. For example, the bit hierarchy key might be:

L8	C3	. . .	T2	C2	T1	C1	L1	D5	D4	D3	D2	D1
22	21	. . .	10	9	8	7	6	5	4	3	2	1

Ideally the bit hierarchy key is ordered so that programs most likely to be the subject of timer preprogramming would have a low value binary number, which would eliminate keystrokes for timer preprogramming the most popular programs. Since all the date information has equal priority, then the D₅D₄D₃D₂D₁bits are first. Next T₁C₁L₁are used, because for whatever date it is necessary to have a time channel and length and T₁C₁L₁are the most probable in each case due to the ordering of the priority vectors inpriority vector storage122. The next bit in the hierarchy key is determined by the differential probabilities of the various combinations. One must know the probabilities of all the channels, times and lengths for this calculation to be performed.

For example, the probability for channels may be:

	channel

	4	7	2	3	5	6	11	13 . . .

priority	0	1	2	3	4	5	6	7 . . .
probability (%)	5	4.3	4	3	2.9	2.1	2	1.8 . . .

The probabilities for times might be:

	time

	6:30 pm	7:00 pm	8:00 pm	7:30 pm . . .

	priority	0	1	2	3 . . .
	probability (%)	8	7.8	6	5 . . .

And, the probabilities for lengths might be:

	length of program (hours)

	0.5	1.0	2.0	1.5	3.0 . . .

	priority	0	1	2	3	4 . . .
	probability (%)	50	20	15	5	4 . . .

The probabilities associated with each channel, time and length, as illustrated above, are used to determine the proper ordering. Since the priority vector tables are already ordered by the most popular channel, time, and length, the order in which to select between the various binary bits for one table, for example selecting between the C₇C₆C₅C₄C₃C₂C₁bits, is already known. The C₁bit would be selected first because as the lowest order binary bit it would select between the first two entries in the channel priority table. Then the C₂bit would be selected and so on. Similarly, the T₁and L₁bits would be used before any of the other time and length bits. A combination of the C₁, T₁, L₁and D₅D₄D₃D₂D₁bits should be used first, so that all the information is available for a channel, date, time and length. The D₅D₄D₃D₂D₁bits are all used because the date bits all have equal priority and all are needed to specify a date even if some of the bits are binary zero.

At this point the bit hierarchy key could be:

• • T₁C₁L₁D₅D₄D₃D₂D₁

The first channel binary bit C, by itself can only select between 2¹=2 channels, and the first two channels have a probability percent of 5 and 4.3, respectively. So the differential probability of C₁is 9.3.

Similarly, the differential probability of T₁is 8+7.8=15.8, and the differential probability of L₁is 50+20=70. If the rules for ordering the bit hierarchy key are strictly followed, then the first 8 bits of the bit hierarchy key should be ordered as:

C₁T₁L₁D₅D₄D₃D₂D₁,

because L₁has the highest differential priority so it should be next most significant bit after D₅, followed by T₁as the next most significant bit, and then C₁as the next most significant bit. Notice that the bit hierarchy key starts with the least significant bit D₁, and then is filled in with the highest differential probability bits. This is for the purpose of constructing the most compact codes for popular programs.

The question at this point in the encoding process is what should the next most significant bit in the hierarchy key be: T₂, C₂, or L₂. This is again determined by the differential probabilities, which can be calculated from the above tables for each bit. Since we are dealing with binary bits, the C₂in combination with C₁selects between 22=4 channels or 2 more channels over C₁alone. The differential probability for C₂is then the additional probabilities of these two additional channels and for the example this is: 4+3=7. In a similar manner C₃in combination with C₁and C₂selects between 2³=8 channels or 4=2^(3-1)more channels over the combination of C₁and C₂. So the differential probability of C₃is the additional probabilities of these four additional channels and for the example this is: 2.9+2.1+2+1.8=8.8. In a similar manner, the differential probabilities of T₂and L₂can be calculated to be 6+5=11 and 15+5=20, respectively. Once all the differential probabilities are calculated, the next step is determining which combinations of bits are more probable.

Now for the above example, which combination is more probable: T₂with C₁L₁, or C₂with T₁L₁, or L₂with T₁C₁. This will determine the next bit in the key. So, which is greater: 11×9.3×70=7161; 7×15.8×70=7742; or 20×15.8×9.3=2938.8? In this case the combination with the greatest probability is 7×15.8×70=7742, which corresponds to C₂with T₁L₁. So, C₂is selected as the next bit in the bit hierarchy key.

The next bit is selected in the same way. Which combination is more probable: C₃with T₁L₁, or T₂with C₁or C₂and L₁, or L₂with C₁or C₂and T₁. For the example shown, which has the greatest probability: 8.8×15.8×70=9732.8; 11×(9.3+7)×70=12551; or 20×(9.3+7)×15.8=5150.8? In this case the combination with the greatest probability is 1×(9.3+7)×70=12551, which corresponds T₂with C₁or C₂and L₁. So, T₂is selected as the next bit in the bit hierarchy key. This procedure is repeated for all the differential probabilities until the entire key is found.

Alternately, the bit hierarchy key can be just some arbitrary sequence of the bits. It is also possible to make the priority vectors interdependent, such as making the length priority vector dependent on different groups of channels. Another technique is to make thebit hierarchy key120 and the priority vector tables122, a function ofclock42, as shown inFIG. 7. This makes it very difficult for the key and therefore the coding technique to be duplicated or copied.

For example it is possible to scramble the date bits in thebit hierarchy key120 as a function of the clock. Changing the order of the bits as a function of the clock would not change the effectiveness of the bit hierarchy key in reducing the number of binary bits for the most popular programs, because the date bits all are of equal priority. This could be as simple as switching the D, and D₅bits periodically, such as every day or week. Thus thebit hierarchy key120 would switch between

. . .	C1	T1	L1	D5	D4	D3	D2	D1	and
. . .	C1	T1	L1	D1	D4	D3	D2	D5.

Clearly other permutations of the bit hierarchy key as a function of the clock are possible.

The priority vector tables could also be scrambled as a function of the clock. For example, the first two channels in the priority channel table could just be swapped periodically. If this technique is followed, then the C^Pof148 inFIG. 7 would change as a function of theclock42. For example,

	channel

	4	7	2	3	5	6	11	13 . . .

priority	0	1	2	3	4	5	6	7 . . .

would change periodically to:

	channel

	7	4	2	3	5	6	11	13 . . .

priority	0	1	2	3	4	5	6	7 . . .

This would be a fairly subtle security technique, because a decoder that was otherwise correct would only fail if those first two channels were being used. Other clock dependencies are also possible to provide security for the coding technique.

However it is derived, thebit hierarchy key120 is determined and stored. Instep154 the binary bits of C_p, D_p, T_p, L_pare rearranged according to thebit hierarchy key120 to create one 22 bit binary number. Then the resulting 22 bit binary number is converted to decimal in the convert binary number to decimal G-code step156. The result is G-code158.

If the priority vector and the bit hierarchy key are well matched to the viewing habits of the general population, then it is expected that the more popular programs would require no more than 3 or 4 digits for the G-code.

Now that the encoding technique has been explained the decoding technique is just reversing the coding technique. This is done according to the flow chart ofFIG. 6. This is the preferred G-code decoding that can be built into G-code decoder38 inVCR14 or the remote controller G-code decoders82 and92 inFIGS. 3 and 5.

Thefirst step102 is to enter G-code104. Next the G-code104 is converted to a 22 bit binary number instep106. Then the bits are reordered instep108 according to thebit hierarchy key120 to obtain the reorderedbits110. Then the bits are grouped together and converted to decimal form instep112. As this point we obtain C_p, D_p, T_p, L_pdata114, which are the indices to the priority vector tables. For the above example, we would have at this step thevector 4 9 1 3. This C_p, D_p, T_p, L_pdata114 is then used in step116 to lookup channel, date, time, and length inpriority vector storage122. TheCDTL118 for the example above is 5 10 19.00 1.5, which meanschannel 5, 10th day of the month, 7:00 PM, and 1.5 hours in length.

If the coding technique is a function of the clock then it is also necessary to make the decoding technique a function of the clock. It is possible to make thebit hierarchy key120 and the priority vector tables122, a function ofclock42, as shown inFIG. 6. This again makes it very difficult for the key and therefore the coding technique to be duplicated or copied. It is also possible to have the decoding and encoding techniques dependent on any other predetermined or preprogrammable algorithm.

Although the above G-code encoding and decoding technique is a preferred embodiment, it should be understood that there are many ways to perform the intent of the invention which is to reduce the number of keystrokes required for timer preprogramming. To accomplish this goal there are many ways to perform the G-code encoding and decoding. There are also many ways to make the encoding and decoding technique more secure besides just making the encoding and decoding a function of the clock. This security can be the result of any predetermined or preprogrammed algorithm.

It is possible in the G-code coding and decoding techniques to use mixed radix number systems instead of binary numbers. For example, suppose that there are only 35 channels, which would require 6 binary bits to be represented; however, 6 binary bits can represent 64 channels, because 26=64. The result is that in a binary number system there are 29 unnecessary positions. This can have the effect of possibly making a particular G-code longer than it really needs to be. A mixed radix number system can avoid this result. For example, for the case of 35 channels, a mixed radix number system with the factors of 7¹and 5⁰can represent 35 combinations without any empty space in the code. The allowed numbers for the 7¹factor are 0, 1, 2, 3, and 4. The allowed numbers for the 5⁰factor are 0, 1, 2, 3, 4, 5, and 6. For example, digital 0 is represented in the mixed radix number system as00. Thedigital number34 is represented in the mixed radix number system as46, because 4*7^1·6*5⁰=34. The major advantage of a mixed radix number system is in prioritizing the hierarchy key. If the first 5 channels have about equal priority and the next 30 are also about equal, then the mixed radix number system allows the two tiers to be accurately represented. This is not to say that a mixed radix number system is necessarily preferable. Binary numbers are easier to represent in a computer and use of a fixed radix number system such as binary numbers allows a pyramid of prioritization to be easily represented in the hierarchy key.

Another feature that is desirable in all of the embodiments is the capability to key in the G-code once for a program and then have the resulting CDTL information used daily or weekly. Ordinarily the CDTL information is discarded once it is used. In the case of daily or weekly recording of the same program, the CDTL information is stored and used until it is cancelled. The desire to repeat the program daily or weekly can be performed by having a “WEEKLY” or “DAILY” button on the remote controller or built into the VCR manual controls. Another way is to use one key, such as the PROG key and push it multiple times within a certain period of time such as twice to specify daily or thrice to specify weekly. For example, if the G-code switch is “ON” and the G-code for the desired program is 99 then daily recording of the program can be selected by the following keystrokes:

• • “PROG99 DAILY PROG” or by:
  • “PROG99 PROG PROG”.

The G-code99 would be converted to CDTL information, which would be stored and used daily in this case. The recording would begin on the date specified and continue daily after that using the same channel time and length information. A slight twist is that daily recording could be automatically suspended during the weekends, because most daily programs are different on Saturday and Sunday.

Once a daily or weekly program is set up, then it can be used indefinitely. If it is desired to cancel a program and if there is a “CANCEL” button on the remote controller or manual control for the VCR, then one way to cancel a program (whether it is a normal CDTL, daily or weekly entry) is to key in the following:

• • “PROG xx CANCEL”, where xx is the G-code.

Again as before there are alternate ways of accomplishing this.

If “on screen programming” is available, then the programs that have been selected for timer preprogramming could be reviewed on the screen. The daily and weekly programs would have an indication of their type. Also the G-codes could be displayed along with the corresponding CDTL information. This would make it quite easy to review the current “menu” and either add more programs or cancel programs as desired.

Atelevision calendar200 according to this invention is illustrated inFIG. 8. As shown, the television calendar has multiple day of year sections202,multiple day sections204, multiple time ofday sections206,channel identifiers208, anddescriptive program identifiers210, including the name of the program, arranged in a manner that is common in television guide publications. Arranged in relation to each channel identifier is a compressed code indication212 or G-code containing the channel, date, time and length information for that entry in the television calendar.FIG. 8 shows how easy it is to perform timer programming. All one needs to do is find the program one wants to watch and enter the compressed code shown in the compressed code indication. This is in contrast to having to deal with all the channel, date, time and length entries separately. At least the channel, date and time are explicitly stated in the television guide. The length is usually only available by searching the guide to find the time ofday section204 where a new program begins and then performing some arithmetic to find the length of the program. Using the compressed G-code avoids all these complications.

For cable television programs, there is an additional issue that needs to be addressed for the compressed G-code to be useful. In a normal television guide, CDTL information is available for all the normal broadcast channels in the form of numbers including the channel numbers, such aschannel 4 or 7. However, for cable channels like HBO, ESPN etc., only the names of the channels are provided in most television listings. The reason for this is that in some metropolitan areas, such as Los Angeles, there may be only one (1) edition of television guide, but there may be quite a few cable carriers, each of which may assign HBO or ESPN to different cable channel numbers. In order for a compressed code such as the G-code to be applicable to the cable channels as published by a wide area television guide publication, the following approach can be used.

First, all the cable channels would be permanently assigned a unique number, which would be valid across the nation. For example, we could assign ESPN tocable channel 1, HBO ascable channel 2, SHO ascable channel 3, etc. This assignment would be published by the television guide publications.

The video cassette recorder apparatus, such as the remote controller, the VCR unit or both, could then be provided with two (2) extra modes: “set” and “cable channel”. One way of providing the user interface to these modes would be to provide two (2) extra buttons: one called SET and one called CABLE CHANNEL. The buttons could be located on the video cassette recorder unit itself or located on a remote controller, as shown inFIGS. 1,3 and5, where SET iselement168 and CABLE CHANNEL iselement170. Of course, other user interfaces are possible.

Next, the television viewer would have to go through a one-time “setting” procedure of his VCR for all the cable channels that he would likely watch. This “setting” procedure would relate each of the assigned numbers for each cable channel to the channel number of the local cable carrier. For example, suppose that the local cable carrier useschannel 6 for ESPN, thencable channel number 1 could be assigned to ESPN, as shown in the following table.

	Cable Channel	Assigned	Channel Number in
	Name carrier	Cable Chan No.	the localcable carrier
	EPSN
	1	6
	6HBO	2	24
	SHO	3	25
	.	.	.
	.	.	.
	.	.	.
	DIS	8	25

The user could perform the “setting” procedure by pushing the buttons on his remote controller as follows:

• • SET 06CABLE CHANNEL 1 PROGRAM
  • SET 24CABLE CHANNEL 2 PROGRAM
  • SET 23CABLE CHANNEL 3 PROGRAM
  • SET 25CABLE CHANNEL 8 PROGRAM

The “setting” procedure would create a cable channel address table162, which would be loaded intoRAM52 ofcommand controller36. For the above example, the cable channel address table162 would have the following information.

	TABLE 162
	CABLE CHANNEL	ADDRESS
	1	6
	2	24
	3	23
	.	.
	.	.
	.	.
	8	25

After the “setting” procedure is performed, the TV viewer can now select-cable channels for viewing by the old way: eg. pushing thekey pad buttons24 will select HBO. He can also do it the new way: eg. by pushingCABLE CHANNEL 2, which will also select HBO. The advantage of the new way is that the television guide will publish [C2] next to the program description, so the viewer will just look up the assigned channel number identifier instead of having to remember that HBO islocal cable channel 24. When the CABLE CHANNEL button is pushed,command controller36 knows that it will look up the local cable channel number in cable channel address table162 to tune the VCR to the correct channel.

For timer preprogramming and for using the compressed G-code, a way to differentiate between broadcast and cable channels is to add an eighth channel bit, which would be set to 0 for normal broadcast channels and 1 for cable channels such as HBO. This eighth channel bit could be one of the low order bits such as the third bit C₃out of the eight channel bits, so that the number of bits to specify popular channels is minimized, whether they be normal broadcast or cable channels. For a normal broadcast channel, the 7 other bits can be decoded according to priority vector C table124. For a cable channel, the 7 other bits can be decoded according to a separate cable channel priority vector table160, which could be stored inROM54 ofmicrocontroller36. The cable channel priority vector table can be set ahead of time for the entire country or at least for an area covered by a particular wide area television guide publication.

A television guide that carries the compressed code known as the G-code will now print the cable channel information as follows:

	6:30 pm
	[C2]
	HBO
	xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx (4679)
	xxxxxx (program description) xxxxxxxxxxxxxxx
	xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

The [C2] in front of HBO reminds the viewer that he needs only to pushCABLE CHANNEL 2 to select HBO. The (4679) is the G-code indication for this particular program.

FIG. 8 shows a section of a television guide. The cable channels all have an assignedcable channel number188 after the cable channel mnemonic. Other than that the cable channel information is arranged the same as the broadcast channels with a compressed G-code212 associated with the channel.

For timer preprogramming, the viewer need only enter the number4679 according to the unit's G-code entry procedure, eg. PROG4679 PROG. The G-code decoder unit will decode this G-code into “cable channel 2” and will also signal thecommand controller36 with acable channel signal164, as shown inFIGS. 1 and 2, because the extra channel bit will be “1” which distinguishes that the G-code is for a cable channel; then, since the association of “cable channel 2” withchannel 24 has been established earlier in the “setting” procedure, the command controller, if it has received a cable channel signal, will immediately look up 2 in the cable channel address table162 to translate it tocable channel 24, which will be used as the recording channel at the appropriate time. By associating the G-code with the assigned cable channel number rather than the local cable channel number, the G-code for that program will be valid in the whole local area, which may have many different cable carriers each of which may have different local cable channel numbers.

To include the cable channel compressed G-code feature, the decoding and encoding algorithms are as shown inFIGS. 9 and 10, respectively. The encoding should be explained first before the decoding. The primary change inFIG. 10 fromFIG. 7 is that a cable channel priority vector table160 has been added and is used in look up priority step180 if a cable channel is being encoded. Also if a cable channel is being encoded then the cable channel bit is added in the correct bit position in the convert C_pD_pT_pL_pto binary numbers step182. This could be bit C₃, as discussed before. The bit hierarchy key could be determined as before to compress the number of bits in the most popular programs; however, it needs to be 23 bits long to accommodate the cable channel bit. The maximum compressed G-code length could still be 7 digits, because 223=8,388,608.

The decoding is shown inFIG. 9 and is just the reverse of the encoding process. Afterstep108, testcable channel bit174 is added and effectively tests the cable channel bit to determine if it is a “1”. If so then thecommand controller36 is signaled viacable channel signal164 ofFIGS. 1 and 2 that theCDTL118 that will be sent to it from G-code decoder38 is for a cable channel. Then the command controller knows to look up the local cable carrier channel number based on the assigned cable channel number. Instep176 ofFIG. 9, the priority vector tables including the cable channel priority vector table160 are used to look up theCDTL118 information.

An alternate to having the command controller receive acable channel signal164 is for the G-code decoder to perform all of the decoding including the conversion from assigned cable channel number to local cable carrier number. This would be the case for the remote controller implementation ofFIG. 3.FIG. 11 shows the implementation of the entire decode algorithm if this step is included. All that needs to be added is convert assigned channel to local cablecarrier channel step166, which performs a lookup in cable channel address table162, if the cable channel bit indicates that a cable channel is involved. Step166 effectively replacesstep174 inFIG. 9.

Another issue that needs addressing is the number of programs that can be preprogrammed. Since the G-code greatly simplifies the process of entering programs, it is likely that the user will quickly learn and want to enter a large number of programs; however, some existing VCRs can only store up to four (4) programs, while some can store as many as eight. Thus, the user may get easily frustrated by the programming limitations of the VCR.

One approach to this problem, is to perform the compressed G-code decoding in the remote controller and provide enough memory there to store a large number of programs, eg. 20 or 40. The remote controller would have the capability of transferring periodically several of these stored programs at a time to the VCR main unit. To provide this capability, extra memory calledstack memory76 is required inside the remote unit, as shown inFIG. 12, which other than that is identical toFIG. 4.Stack memory76 can be implemented with a random access memory, which may in fact reside in the microcontroller itself, such asRAM62.

Thestack memory76 is where new entry, insertion & deletion of timer preprogramming information is carried out. It is also where editing takes place. The top memory locations of the stack, for example the first 4 locations, correspond exactly to the available timer preprogramming memory in the VCR main unit. Whenever the top of the stack memory is changed, the new information will be sent over to the VCR main unit to update it.

FIG. 13 shows the sequence of events when the user enters a G-code program on the keypad of the remote controller. For illustration purposes, suppose the VCR main unit can only handle four (4) programs. Suppose also that the stack memory capacity is 20 timer preprograms. Referring to the flow chart inFIG. 13, when the user enters a G-code instep230, themicrocontroller60 first decodes it into the CDTL information instep234 and displays it on the display unit with the additional word “entered” also displayed. The microcontroller then enters the decoded program into the stack memory instep236.

If this is the first program entered, it is placed at the top location of the stack memory. If there are already programs in the stack memory, the newly entered program will first be provisionally placed at the bottom of the stack memory. The stack memory will then be sorted into the correct temporal order instep240, so that the earliest program in time will appear in the top location and the last program in time will be at the bottom. Notice that the nature of the temporally sorted stack memory is such that if stack memory location n is altered, then all the locations below it will be altered.

For example, suppose the stack memory has six (6) entries already temporally ordered, and a new entry is entered whose temporal ordering places it in location3 (1 being the top location). If this entry is placed intolocation3, information which was inlocation3,4,5,6 will be shifted tolocations4,5,6, and7.Locations1 and2 will remain unchanged.

Themicrocontroller60, after doing the temporal ordering, checks in step242 whether the first n entries have changed from before, where for the current example n equals 4. In this case, since a new program has been entered intolocation3, what used to be inlocation3 now moves tolocation4. Since the VCR's main unit program menu of 4 entries should correspond exactly tolocation1 through4 of the stack memory,entries3 and4 on the VCR main unit must now be revised. The microcontroller therefore sends out thenew entries3 &4 to the main unit, in step244 ofFIG. 13. If the newly entered program, after temporal ordering, gets entered intolocation5, thenentries1 through4 have not changed from before and the microcontroller will not send any message to the VCR main unit and the microcontroller will just resume monitoring theclock85 and the keyboard88 as per step246. It is assumed that when the user enters the G-code instep230, the remote controller is pointed at the VCR main unit. The other steps ofFIG. 13 happen so fast that the changes are sent in step244 while the remote controller is still being pointed at the VCR main unit.

If the user decides to delete a program instep232, the deletion is first carried out in the stack memory. If the first4 entries are affected, the microcontroller will send the revised information over to the VCR main unit. If the first4 entries are not affected, then again the remote controller unit will not send anything. The deletion will only change the lower part of the stack (lower meaninglocation5 to20). This new information will be sent over to the VCR main unit at the appropriate time.

In the meantime, the VCR main unit will be carrying out its timer programming function, completing its timing preprogramming entries one by one. By the time all 4 recording entries have been completed, the stack in the remote must send some new entries over to “replenish” the VCR main unit (if the stack has more than 4 entries).

Thereal time clock85 in the remote controller unit is monitored by the microcontroller to determine when the programs in the main unit have been used up. Referring to the flow chart inFIG. 14, the microcontroller periodically checks the clock and the times for the programs at the top of the stack in step250 (say the first 4 entries), which are identical to the VCR's main unit's menu. If on one of the periodic checks, it is determined that the recording of the main unit's menu is complete, then if there are more entries in the stack, which is tested instep252, the display unit will be set to a blinking mode or display a blinking message instep258 to alert the user to send more programs. Next time the user picks up the remote unit, the blinking will remind him that the VCR main unit's program menu has been completed and it is time to replenish the VCR main unit with program entries stored in the remote. The user simply picks up the remote and points it towards the VCR main unit and presses. “ENTER”. This will “pop” the top of the stack memory instep260, ie. pop all the entries in the stack up by four locations. The microcontroller will then send the new “top of the stack” (ie. top 4 entries) over to the VCR main unit instep262. This process will repeat until the whole stack has been emptied.

Another preferred embodiment of an apparatus for using compressed codes for recorder preprogramming is theinstant programmer300 ofFIG. 15. Theinstant programmer300 hasnumber keys302, which are numbered0 through9, a CANCEL key304, aREVIEW key306, aWEEKLY key308, a ONCE key310 and a DAILY (M–F)key312, which are used to program theinstant programmer300. A lid normally covers other keys, which are used to setup theinstant programmer300. Whenlid314 is lifted, the following keys are revealed: SAVE key316,ENTER key318,CLOCK key320, CH key322, ADD TIME key324,VCR key326,CABLE key328, and TEST key330. Other features ofinstant programmer300 shown onFIG. 15 are:liquid crystal display350 and red warninglight emitting diode332. The front elevation viewFIG. 16 ofinstant programmer300 shows front infrared (IR)diode340 mounted on thefront side338. By placinginstant programmer300 in front of the equipment to be programmed such asvideo cassette recorder370,cable box372, andtelevision374, as shown inFIG. 19, the front infrared (IR)diode340 can transmit signals to control program recording. An IRtransparent cover336 covers additional IR transmission diodes, which are explained below.

FIG. 18 shows a detail of theliquid crystal display350.Certain text354 is at various times visible on the display and there is anentry area356. Time bars352 are displayed at the bottom of the display and their function is described below.

A companion element to theinstant programmer300 is the mountingstand360, shown inFIG. 17, which is designed to holdinstant programmer300 between left raisedside362 and right raisedside364. Theinstant programmer300 is slid between left raisedside362 and right raisedside364 until coming to a stop at front alignment flange365, which is at the front of mountingstand360 and connected across left raisedside362 and right raisedside364. Togetherelements362,364 and the front alignment flange provide alignment forinstant programmer300 so that IRtransparent cover336 and theIR diodes342,344,346 and348, shown inFIG. 17 are properly aligned for transmission, when the instant programmer is used as shown inFIG. 20. The mountingstand360 has analignment flange366, which has the purpose of aligning the back edge of mountingstand360, which is defined as the edge along whichalignment flange366 is located, along the front side of a cable box or VCR, or similar unit as shown inFIG. 20. When aligned as shown inFIG. 20, the mountingstand360 aligns theinstant programmer300 so that theleft IR diode342, downIR diode344, two-back IR diodes346 andright IR diode348, as shown inFIG. 17, are in position to transmit signals tovideo cassette recorder370 andcable box372, as necessary. If the VCR and/or cable box functions are located within thetelevision374 itself, then theinstant programmer300 could be positioned to transmit to thetelevision374, either in the manner ofFIG. 19 or by placing the mounting stand on top of the television in the manner ofFIG. 20.

By using mountingstand360, the user only need to align the mountingstand360, and theinstant programmer300 once with the equipment to be programmed rather than having the user remember to keep theinstant programmer300 in the correct location to transmit via front infrared (IR)diode340, as shown inFIG. 19. Current experience with various remote controllers shows that it is difficult at best to keep a remote controller in a fixed location, for example, on a coffee table. The mountingstand360 solves this problem by locating theinstant programmer300 with the equipment to be controlled. Theleft IR diode342, downIR diode344, two backIR diodes346 andright IR diode348 are positioned to transmit to the left, downward, backward, and to the right. The downward transmitter assumes that mountingstand360 will be placed on top of the unit to be programmed. The left and right transmission allows units to the left or right to be programmed. The backward transmission backIR diodes346 are provided so that signals can bounce off walls and other objects in the room. Thefront IR diode340, theleft IR diode342, theright IR diode348 and thedown IR diode344 are implemented with 25 degree emitting angle diodes. Two back IR diodes are provided for greater energy in that direction and are implemented with 5 degree emitting angle diodes, which focus the energy and provide for greater reflection of the IR energy off of walls or objects in the room.

Most VCR's and cable boxes can be controlled by an infrared remote controller; however, different VCR's and cable boxes have different IR codes. Although there are literally hundreds of different models of VCR's and cable boxes, there are fortunately only tens of sets of IR codes. Each set may have a few tens of “words” that represent the different keys required, e.g. “power”, “record”, “channel up”, “channel down”, “stop”, “0”, “1”, “2” etc. For the purpose of controlling the VCR and cable box to do recording, only the following “words” are required: “0”, “1”, “2”, “3”, “4”, “5”, “6”, “7”, “8”, “9”, “power”, “record”, “stop”. The IR codes for these words for all the sets are stored in the memory of theinstant programmer300, which is located inmicrocomputer380 ofFIGS. 21 and 22. During setup of theinstant programmer300, the user interactively inputs to theinstant programmer300 the type and model of his VCR and cable box. The correct set of IR codes will be recalled from memory during the actual control process. In the case where the user only has a VCR, the infrared (IR) codes for that particular VCR will be recalled to control the VCR. In the case where the user has a VCR and a cable box, the IR codes “power”, “record”, “stop” will be recalled from the set that corresponds to the VCR whereas the IR codes for “0” through “9” will be recalled from the set that corresponds to the cable box. The reason is that in this case, the cable box controls the channel switching. Hence the channel switching signals “0” through “9” must be sent to the cable box instead of the VCR.

Initially, the user performs a setup sequence. First, the user looks up the number corresponding to the model/brand of VCR to be programmed in a table, which lists the VCR brand name and a two digit code. Then with the VCR tuned toChannel 3 orChannel 4, whichever is normally used, the user turns the VCR “OFF”. Then the user presses theVCR key326. When the display shows VCR, the user presses the two-digit code looked up in the VCR model/brand table (for example 01 for RCA). The user points theinstant programmer300 at the VCR and then pressesENTER key318. The red warninglight emitting diode332 will flash while it is sending a test signal to the VCR. If the VCR turned “ON” and changed to Channel 09, the user presses theSAVE key316 and proceeds to the set clock step. If the VCR did not turn “ON” or turned “ON” but did not change to Channel 09 the user pressesENTER key318 again and waits until red warninglight emitting diode332 stops flashing. Theinstant programmer300 sends the next possible VCR code, while the red warninglight emitting diode332 is flashing. If the VCR turns “ON” and changed to Channel 09 the user pressesSAVE key316, otherwise the user pressesENTER key318 again until the VCR code is found that works for the VCR. The display shows “END” if all possible VCR codes for that brand are tried. If so, the user pressesVCR key326 code00 and then ENTER key318 to try all possible codes, for all brands, one at a time.

Once the proper VCR code has been found and saved, the next setup step is to set the clock oninstant programmer300. First, the user presses theCLOCK key320. When the display shows: “YR:”, the user presses the year (for example 90), then pressesENTER key318. Then the display shows “MO:”, and the user presses the month (for example 07 is July), and then pressesENTER key318. This is repeated for “DA:” date (for example 01 for the 1st), “Hr:” hour (for example 02 for 2 o'clock), “Mn:” minute (for example 05 for 5 minutes), and “AM/PM:” 1 for AM or 2 for PM. After this sequence, the display will show “SAVE” for a few seconds and then the display will show the current time and date that have been entered. It is no longer necessary for the user to set the clock on his/her VCR.

Next, if theinstant programmer300 is also to be used as a cable box controller, then the setup steps are as follows. First, the number corresponding to the model/brand of cable box (converter) to be controlled is looked up in a cable box model brand table, that lists cable box brands and corresponding two digit codes. The VCR is tuned to Channel 03 or 04 and turned “OFF”. Then the cable box is tuned to Channel 02 or 03, whichever is normal, and left “ON”. Then theCABLE key328 is pressed. When the display shows: “CA B-:” the user enters the two digit code looked up in cable box model brand table, points theinstant programmer300 at the cable box (converter) and pressesENTER key318. The red warninglight emitting diode332 will flash while it is sending a test signal to the cable box. If the cable box changed to Channel 09: then the user pressesSAVE key316; however, if the cable box did not change to Channel 09 the user pressesENTER key318 again and waits until red warninglight emitting diode332 stops flashing, while the next possible code is sent. This is repeated until the cable box changes to Channel 09 and when it does the user pressesSAVE key316. If the display shows “END” then the user has tried all possible cable box codes for that brand. If so, the user presses cable code00 and then ENTER key318 to try all possible brand's codes, one at a time.

For some people (probably because they have cable or satellite), the channels listed in their television guide or calendar are different from the channels on their television or cable. If they are different, the user proceeds as follows. First, the user presses theCH key322. The display will look like this: “Guide CH TV CH”. Then the user presses the channel printed in the television guide or calendar (for example, press 02 for channel 2), and then the user presses the channel number that the printed channel is received on through his/her local cable company. Then the user pressesENTER key318. This is repeated for each channel listing that is on a different channel than the printed channel. When this procedure is finished the user pressesSAVE key316.

Typically the television guide or calendar in the area will have a chart indicating the channel number that has been assigned to each Cable and broadcast channel, for example: HBO, CNN, ABC, CBS, NBC, etc. This chart would correspond, for example, to the left two columns ofFIG. 28. For example, suppose the television guide or calendar has assignedchannel 14 to HBO but the user's cable company delivers HBO onchannel 18. Since the channel numbers are different, the user needs to use theCH key322. The user will press the CH button (the two blank spaces under the display “Guide CH” will flash). The user then presses14. (now the two blank spaces under the display “TV CH” will flash). The user then presses18 and then ENTERkey318. This is repeated for each channel that is different. When finished, the user pressesSAVE key316.

After the channel settings have been saved, the user may review the settings by pressing CH key322 and then REVIEW key306. By repeated pressing of theREVIEW key306 each of the set channels will scroll onto the display, one at a time.

Then the user can test to make sure that the location of theinstant programmer300 is a good one. First, the user makes sure that the VCR is turned “OFF” but plugged in and makes sure that the cable box (if there is one) is left “ON”. Then the user can press the TEST key330. If there is only a VCR, then if the VCR turned “ON”, changed to channel 09 and started recording, and then turned “OFF”, then the VCR controller is located in a good place.

If there is also a cable box., then if the VCR turned “ON”, the cable box turned to channel 09 and the VCR started recording, and then the VCR stopped and turned “OFF”, then theinstant programmer300 is located in a good place.

To operate theinstant programmer300, the VCR should be left OFF and the cable box ON. The user looks up in the television guide the compressed code for the program, which he/she wishes to record. The compressed code212 is listed in the television guide, as shown inFIG. 8. The television guide/calendar that would be used with this embodiment would have the same elements as shown onFIG. 8 except thatelement188 ofFIG. 8 is not required. The compressed code212 for the program selected by the user is entered into theinstant programmer300 by using thenumber keys302 and then the user selects how often to record the program. The user presses the ONCE key310 to record the program once at the scheduled time, or the user presses the WEEKLY key308 to record the program every week at the same scheduled time until cancelled or the user presses the DAILY (M–F)key312 to record the program each day Monday through Friday at the same scheduled time until cancelled. This is most useful for programs such as soapbox operas that air daily, but not on the weekend. To confirm the entry, theinstant programmer300 will immediately decode the compressed code and display the date, channel and start time of the program entered by the user. The length of the entered program is also displayed bytime bars352 that run across the bottom of the display. Each bar represents one hour (or less) of program.

Then the user just needs to leave theinstant programmer300 near the VCR and cable box so that commands can be transmitted, and at the right time, theinstant programmer300 will turn “ON” the VCR, change to the correct channel and record the program and then turn the VCR “OFF”. The user must just make sure to insert a blank tape.

TheREVIEW key306 allows the user to step through the entered programs. These are displayed in chronological order, by date and time. Each time theREVIEW key306 is pressed, the next program is displayed, until “END” is displayed, when all the entered programs have been displayed. If theREVIEW key306 is pressed again the display will return to the current date and time.

If the user wishes to cancel a program, then the user pressesREVIEW key306 until the program to cancel is displayed, then the user presses CANCEL key304. The display will say “CANCELLED”. Also, any time the user presses a wrong number, pressing the CANCEL key304 will allow the user to start over.

Certain television programs, such as live sports, may run over the scheduled time slot. To ensure that the entire program is recorded, the user may press the ADD TIME key324 to increase the recording length, even while the program is being recorded. The user presses theREVIEW key306 to display the program, then pressesADD TIME key324. Each timeADD TIME key324 is pressed, 15 minutes is added to the recording length.

When the current time and date is displayed, the amount of blank tape needed for the next 24 hours is also displayed by the time bars352 that run across the bottom of the display. Each bar represents one hour (or less) of tape. The user should check this before leaving the VCR unattended to ensure that there is enough blank tape.

Each time a program code is entered, theinstant programmer300 automatically checks through all the entries to ensure that there is no overlap in time between the program entries. If the user attempts to enter a program that overlaps in time with a program previously entered, then the message “CLASH” appears. Then, as summarized by step432 ofFIG. 23, the user has the following options: 1) if the user wishes to leave the program previously entered and forget about the new one, the user does nothing and after a short time delay, the display will return to show the current time and date;2) if the user wishes the program which starts first to be recorded to its end, and then to record the remainder of the second program, then the user presses ONCE key310, DAILY (M–F)key312, or WEEKLY key308 again (whichever one the user pushed to enter the code). If the programs have the same starting time, then the program most recently entered will be recorded first. If on being notified of the “CLASH”, the user decides the new program is more important than the previously entered program, then the user can cancel the previously entered program and then re-enter the new one.

In some locations, such as in some parts of Colorado, the cable system airs some channels three (3) hours later/earlier than the times listed in the local television guide. This is due to time differences depending on whether the channel is received on a east or west satellite feed. For the user to record theprogram 3 hours later than the time listed in the television guide the procedure is as follows. First the user enters the code for the program and then presses SAVE key316 (for +) and then presses ONCE key310, DAILY (M–F)key312, or WEEKLY key308, as desired. For the user to record theprogram 3 hours earlier than the time listed in the television guide the procedure is as follows. First the user enters the code for the program and then presses ENTER key318 (for −) and then presses ONCE key310, DAILY (M–F)key312, or WEEKLY key308, as desired. Theinstant programmer300 will display the time that the program will be recorded, not the time shown in the television guide.

There are certain display messages to make theinstant programmer300 more user friendly. The display “LO BATT” indicates that the batteries need replacement. “Err: ENTRY” indicates an invalid entry during set up. “Err: CODE” indicates that the program code number entered is not a valid number. If this is displayed the user should check the television guide and reenter the number. “Err: DATE” indicates the user may have: tried to select a daily recording (Monday to Friday) for a Saturday or Sunday program; tried to select weekly or daily recording for a show more than 7 days ahead, because theinstant programmer300 only allows the weekly or daily recording option to be used for the current weeks' programs (±7 days); or tried to enter a program that has already ended. “FULL” indicates that the stack storage of the programs to be recorded, which is implemented in random access memory (RAM) inside theinstant programmer300 has been filled. The user could then cancel one or more programs before entering new programs. “EMPTY” indicates there are no programs entered to be recorded. The number of programs to be recorded that can be stored in theinstant programmer300 varies depending on the density of RAM available and can vary from 10 to more.

FIG. 21 is a schematic of the circuitry needed to implement theinstant programmer300. The circuitry consists ofmicrocomputer380,oscillator382,liquid crystal display384,key pad386, fiveway IR transmitters390 and red warninglight emitting diode332. Themicrocomputer380 consists of a CPU, ROM, RAM, I/O ports, timers, counters and clock. The ROM is used for program storage and the RAM is used among other purposes for stack storage of the programs to be recorded. Theliquid crystal display384 isdisplay350 ofFIGS. 15 and 18. Thekey pad386 implements all the previously discussed keys. The fiveway IR transmitters390 consists of front infrared (IR)diode340, leftIR diode342, downIR diode344, two backIR diodes346 andright IR diode348.FIG. 22 shows the detailed schematic of theinstant programmer300 circuitry and previously identified elements are identified by the same numbers. The microcomputer can be implemented with a NEC uPD7530x part, which can interface directly with the display, the keypad, the light emitting diodes and the oscillator. The 25 degree IR diodes can be implemented with NEC 313 AC parts and the 5 degree IR diodes can be implement with Liton 2871 C IR diodes.

The flowcharts for the program that is stored in the read only memory (ROM) of themicrocomputer380 that executes program entry, review and program cancellation, and record execution are illustrated inFIGS. 23,24, and25, respectively. TheFIG. 23 for program entry, which process was described above, consists of the following steps: display current date, time and time bars step402, which is the quiescent state of instant programmer300; scan keyboard to determine if numeric decimal compressed code entered step404; display code as it is entered step406; user checks if correct code entered step408 and user presses CANCEL key304 step428; user advances or retards start time by three hours by pressing SAVE key316 or ENTER key318 step410; user presses ONCE key310, WEEKLY key308 or DAILY key312 key step412; microcomputer decodes compressed code into CDTL step414; test if conflict with stored programs step416, if so, display “CLASH” message step420, user presses ONCE key310, WEEKLY key308 or DAILY key312 step422, then accommodate conflicting entries step432, as described above in the discussion of the “CLASH” options, and entry not saved step424; set display as date, channel, start time and duration (time bars) for ONCE, or DA, channel, start time and duration for DAILY, or day of week, channel, start time and duration for WEEKLY step418; user presses ADD TIME key324, which adds 15 minutes to record time step426; user checks display step430; enter program on stack in chronological order step434 wherein the stack is a portion of the RAM of microcontroller380; and calculate length of tape required and update time bars step436.

TheFIG. 24 flowchart for review and cancellation, which process was described above, consists of the following steps: display current date, time and time bars step402;REVIEW key306 pressedstep442; test if stackempty step444, display “EMPTY”step446, and return to current date andtime display step448; display top stack entry step450; user pressesADD TIME key324step452 and update time bars step460; user pressesREVIEW key306step454 and scroll stack up oneentry step462; user presses CANCEL key304step456 and display “CANCELLED” and cancel program step464; and user does nothing step458 and wait 30seconds step466, wherein the 30 second timeout can be implemented in the timers ofmicrocomputer380.

TheFIG. 25 flowchart for record execution, which is the process of automatically recording a program and which was described above, consists of the following steps: compare start time of top program in stack memory withcurrent time step472; test if three minutes before start time ofprogram step474; startred warning LED332 blinking for 30seconds step476; display channel, start time and blinking “START”message step478, is correct start time reachedstep480 and send power ON signal to VCR and display “REC”message step482; test if a cable box is input toVCR step484, send channel switching signals toVCR step486 and send channel switching signals tocable box step488; send record signals toVCR step490; compare stop time withcurrent time step492, test if stop time reachedstep494 and display “END”message step496; send stop signals toVCR step498; send power OFF signal toVCR step500; and popprogram stack step502.

FIG. 26 is a flowchart of the method for encoding channel, date, time and length (CDTL) into decimalcompressed code510. This process is done “offline” and can be implemented on a general purpose computer and is done to obtain the compressed codes212 that are included in the, program guide or calendar ofFIG. 8. The first step in the encoding method is the enter channel, date, time and length (CDTL)step512 wherein for a particular program the channel, date, start time andlength CDTL514 of the program are entered. The next step is the lookup assignedchannel number step516, which substitutes an assignedchannel number522 for each channel518. Often, for example for network broadcast channels, such aschannel 2, the assigned channel number is the same; however, for a cable channel such as HBO a channel number is assigned and is looked up in a cable assigned channel table520, which would essentially be the same as the first two columns of the table ofFIG. 28. Next, the lookup priority of channel, date and time/length in priority vector tables step524 performs a lookup in priority vector channel (C) table526, priority vector date (D) table528 and priority vector time/length (TL) table530 using the indices of channel, date and time/length, respectively, to produce the vector C_p, D_p,TL_p532. The use of a combined time/length (TL) table to set priorities recognizes that there is a direct relationship between these combinations and the popularity of a program. For example, at 6:30 PM, a short program is more likely to be popular than a 2 hour program, because it may be the dinner hour.

The channel priority table is ordered so that the most frequently used channels have a low priority number. An example of the data that is in the priority vector C table526 follows.

	channel

	4	7	2	3	5	6	11	13 . . .

priority	0	1	2	3	4	5	6	7 . . .

Generally the dates of a month all have an equal priority or equal usage, so the low number days in a month and the low number priorities would correspond in the priority vector D table528 as in the following example.

	date

	1	2	3	4	5	6	7	8	9	10 . . .

priority	0	1	2	3	4	5	6	7	8	9 . . .

The priority of the start times and length of the programs could be arranged in a matrix that would assign a priority to each combination of start times and program lengths so that more popular combinations of start time and length would have a low priority number and less popular combinations would have a high priority number. For example, a partial priority vector T/L table530 might appear as follows.

Priority TL TABLE

TIME

Length (hrs)	6:30 pm	7:00 pm	7:30 pm	8:00 pm

.5	8	4	7	10 . . .
1.0	12	15	13	18 . . .
1.5	20	19	17	30 . . .

Suppose the channel, date, time and length (CDTL)514 data ischannel5, Feb. 10, 1990, 7:00 PM and 1.5 hours in length, then the C_p, D_p, TL_pdata532 for the above example would be 4 9 19. The next step is the convert C_p, D_p, TL_pto binary numbers and concatenate them into onebinary number step534, resulting in the data word . . . TL₂TL₁. . . C₂C₁. . . D₂D₁536. For the example given above, converting the . . . TL₂TL₁. . . . C₂C₁. . . D₂D₁536 word to binary would yield the three binary numbers: . . . 0010011, . . . 0100, . . . 01001. The number of binary bits to use in each conversion is determined by the number of combinations involved. This could vary depending on the implementation; however one preferred embodiment would use eight bits for C_p, denoted as C₈C₇C₆C₅C₄C₃C₂C₁, which would provide for 256 channels, five bits for D_p, which can be denoted as D₁D₄D₃D₂D₁, would provide for 31 days in a month, and fourteen bits for TL_p, denoted as TL₁₄. . . TL₃TL₂TL₁, which would provide for start times spaced every 5 minutes over 24 hours and program lengths in increments of 5 minute lengths for programs up to 3 hours in length and program length in increments of 15 minute lengths for programs from 3 to 8 hours in length. This requires about 288*(36+20)=16,128 combinations, which are provided by the 2**14=16, 384 binary combinations. Altogether there are 8+5+14=27 bits of information TL₁₄. . . TL₂TL₁C₈. . . C₂C₁D₅. . . D₂D₁. For the above example padding each number with zeros and then concatenating them would yield the 27 bit binary number: 000000000100110000010001001.

The next step is to usebit hierarchy key540, which can be stored in read only memory64 to perform the reorder bits of binary number according to bit hierarchykey step538. As described previously, abit hierarchy key540 can be any ordering of the . . . TL₂TL₁. . . C₂C₁. . . D₂D₁536 bits and in general will be selected so that programs most likely to be the subject of timer preprogramming would have a low value compressed code212, which would minimize keystrokes. The ordering of the bit hierarchy key can be determined by the differential probabilities of the various bit combinations as previously discussed. The details of deriving abit hierarchy key540 were described relative tobit hierarchy key120 and the same method can be used forbit hierarchy key540. For example, the bit hierarchy key might be:

TL8	C3	. . .	TL10	C2	TL1	C1	L1	D5	D4	D3	D2	D1
27	26	. . .	10	9	8	7	6	5	4	3	2	1

The next step is the combine groups of bits and convert each group into decimal numbers and concatenate into onedecimal number step542. For example, after reordering according to the bit hierarchy key, the code may be 000000001010010000010001001, which could be grouped as 00000000101001000, 0010001001. If these groups of binary bits are converted to decimal as328,137 and concatenated into one decimal number, then the resulting decimal number is 328137. The last encoding step is the permutatedecimal number step546, which permutes the decimal number according to permutation function544 that is dependent on the date548 and in particular the month and year and provides a security feature for the codes. After the permutatedecimal number step546, the decimal compressed code G₈. . . G₂G₁550 may, for example, be 238731. These encoded codes are then included in a program guide or calendar as in the compressed code indication212 ofFIG. 8.

FIG. 27 is a flowchart of the method for decoding a decimal compressed code into channel, date, time and length560, which isstep414 ofFIG. 23. Once the decimal compressed code G₈. . . G₂G₁564 is entered instep562, it is necessary to invert the permutation function ofsteps544 and546 ofFIG. 26. The first step is the extractday code step566; which extracts the day code for the program in the decimal compressed code and passes the day code to step568, which; also receives thecurrent day574 from theclock576, which is implemented bymicrocomputer380 inFIGS. 21 and 22. Theclock576 also sends the current month and year to the permutation function570, which is dependent on the month and year. Then step568 performs the function: if day code is same or greater than current day from clock, then use permutation function for month/year on clock, otherwise use permutation function for next month after the month on the clock and use next year if the month on the clock is December. In other words, since there is provision for preprogramming recording for one month or 31 days ahead, if the day for the program is equal to or greater than the current day of the month, then it refers to a day in the present month; otherwise, if the day for the program is less than the current day of the month, it must refer to a program in the next month. The extractday code step566, which must be performed before the invert permutation of decimalcompressed code step580, is accomplished by apriori knowledge of how the permutatedecimal number step546 ofFIG. 26 is performed relative to the day code information.

The selectedpermutation method578 is used in the invert permutation of decimalcompressed code step580. For the example given above, the output ofstep580 would be: 328137. The next step is the convert groups of decimal numbers into groups of binary numbers and concatenate binary groups into onebinary number step584, which is the inverse ofstep542 ofFIG. 26 and for the above example would result in the binary code: 000000001010010000010001001. Then thebit hierarchy key588 is used in the reorder bits of binary number according to bit hierarchykey step586, which inverts step.538 ofFIG. 26 to obtain 000000000100110000010001001 for the above example, which is . . . TL₂TL₁. . . C₂C₁. . . D₂D₁582 corresponding to536 ofFIG. 26. The next step is to group bits to form three binary numbers TL_b, C_b, D_band convert to decimal numbers step590 resulting in C_p, D_p,TL_p592, which for the example above would be:4,9,19, and which are priority vectors for channel, day and time/length, which in turn are used to lookup channel, day, time and length604 in priority vector channel (C) table598, priority vector date (D) table600, and priority vector time/length (TL) table602, respectively.

The lookup localchannel number step606 looks up the local channel612 given the assignedchannel number608, in the assigned/local channel table610, which is setup by the user via theCH key322, as explained above. An example of the assigned/local channel table610 is the right two columns of the assigned/local channel table620 ofFIG. 28. The correspondence between the assigned channel numbers, such as624 and628, and the local channel numbers, such as626 and630 is established during setup by the user. For the example,FIG. 28 shows an exact correspondence between the assignedchannel number 5 and thelocal channel number 5. The last step is the append month and year to day toform date step614. The correct month and year are obtained fromstep568 and are again dependent on whether the day code is equal to or greater than the day from the clock or less than the day from the clock. If the day code is equal to or greater than the day from the clock, the month and year as shown on the clock are used, otherwise the next month is used and the next year is used if the clock month is December. The result is the channel, date, time and length (CDTL)618, which for the above example would bechannel 5, Feb. 10, 1990, 7:00 PM and 1.5 hours in length.

Another preferred embodiment is an apparatus and method to enable a user to selectively record information designated by a digital compressed code. Specifically this apparatus would allow a user to record for later viewing, detailed information associated with an advertisement or similar brief description of a service, product, or any information including public service information.

The advertisement could be print advertisement or broadcast advertisement on television or any other media, such as radio, electronic networks or bulletin boards. The advertisement would have associated with it a digital code, herein referred to as an I code. In print advertisement the digital code would be printed along with the advertisement.FIG. 29ashows anexample print advertisement650 for an automobile and printed in the advertisement is a decimal code for information (I code)652. This code can be identified as anI code652, because the leading digit is a zero, as will be explained below. As shown inFIG. 29a, the use of I codes is very space efficient, which is very important in advertising.

FIG. 29bshows an exampletelevision broadcast advertisement654 with anI code652. The user would identify this code as aI code652, because the leading digit is zero. It may be very expensive to run a long advertisement during prime time when the majority of viewers are watching television; however, a short advertisement could be run during prime time with the I code and then the user could enter the I code intoinstant programmer300, which would command the recording of the longer advertisement for the automobile during the nonprime time. The additional information could be broadcast early in the morning, for example, between midnight and six o'clock in the morning. At this time the broadcast rates are low and it is economical to broadcast detailed information or advertisements of many items such as automobiles and real estate. It would also be possible to transmit movie previews at that time of night.

The reader of print advertisement, the viewer of television and the consumer of any other media, such as radio, would select what additional information was of interest and enter the associated I code intoinstant programmer300, which would then command the recording of the detailed information late at night. The user could then view these at his/her leisure.

Theinstant programmer300 can be used for recorder preprogramming for information using I codes; however, there are some important differences when the device is used for I codes.

A primary difference is that I codes that are entered into theinstant programmer300 are used within the next twenty four hours. The user would read, see or hear the advertisement and enter the I code associated with the advertisement into theinstant programmer300, which would then at the right time sometime in the next 24 hours, and generally in the middle of the night, record the advertisement, by tuning to the proper channel and turning recording on and off for a video cassette recorder. In normal recorder preprogramming, using G codes, theinstant programmer300 decodes thetelevision broadcast advertisement654 into CDTL (channel, date, time, and length). For anI code652, theinstant programmer300 would decode theI code652 into CTL (channel, time and length) only, because the date is known to be in the next twenty four hours. Suppose the time is now June 20th at 6 p.m. If a user enters an I code, which decodes tochannel 2, start time 2:00 a.m., andlength 10 minutes, then the VCR would start recording on June 21st at 2:00 a.m. for 10 minutes.

The hardware for theinstant programmer300 used with decimal codes for information (I codes) can be identical to the design illustrated inFIGS. 15,16,17,17A,18,19,20,21 and22 and described in the associated specification.

The flowcharts for the programs that are stored in the read only memory (ROM) of themicrocomputer380 that execute program entry, review and program cancellation, and record execution are illustrated inFIGS. 23,24, and25, respectively for use of G codes for preprogramming a VCR for program recording.

The programs for use of theinstant programmer300 with I codes for recording information according to this preferred embodiment are in general different; however, the program for review and program cancellation (seeFIG. 24) and record execution (seeFIG. 25) are the same. However, the program that is stored in the read only memory (ROM) of themicrocomputer380 that executes on entry of an I code is different and is shown inFIG. 30. The entry of an I code is determined by inspecting the leading digit of the entered code. If the leading digit is not zero then a G code has been entered, because G codes never have leading zeros, and the flowgraph ofFIG. 23 will be executed. If the leading digit is a zero then an I code has been entered.Steps702,704,706,708 and710 ofFIG. 30 are identical tosteps402,404,406,408 and410 inFIG. 23. The test for a G code or an I code is done in test whether leading digit is zerostep711, which will either branch to step412 ofFIG. 23 if the entered code is a G code, or continue with the next step ofFIG. 30.

The flowchart for entry of the I code inFIG. 30 consists of the following steps: display current date, time and time bars step702, scan keyboard to determine if I code entered step704, display I code as it is enteredstep706, user checks if correct code enteredstep708, user advances or retards start time by three hours by pressing SAVE key316 orENTER key318step710, test whether leading digit is zerostep711, user presses ONCE key310 step712, microcomputer decodes I code into CTL step714, test if conflict with stored programs step716, set display as channel, start time and duration (time bars) step718, display “CLASH”message step720, user presses ONCE key310step722, entry not savedstep724, accommodate conflicting entries step732, user presses CANCEL key304step728, enter program on stack inchronological order step734, and calculate length of tape required and update time bars step736.FIG. 30 illustrates the order and relationships between the steps for I code entry. If the user presses WEEKLY key308 or DAILY (M–F)key312 instead of the ONCE key310, then theinstant programmer300 will interpret these as if the ONCE key310 had been pressed. The stack memory of the enter program on stack inchronological order step734 allows the user to enter multiple digital codes for information, which will all be decoded and entered in order into the stack for later execution when the proper time arrives.

In order to use I codes with advertisements, the I codes have to first be encoded.FIG. 31 is a flowchart of the method for encoding channel, time and length (CTL) for an information broadcast into an I code. This process is done “offline” and can be implemented on a general purpose computer and is done to obtain aI code854 that can be included in an advertisement, such as shown inFIGS. 29aand29b.

In general the I codes are encoded to be compressed coded indications, each representative of, and compressed in length from, the combination of separate channel, start time and a length indications. In print advertisement and also in television broadcasts, there is simply not enough area to separately spell out the channel, start time, and length. The I codes solve this problem by encoding channel, start time and length into one compressed digital code.

The first step in one preferred encoding method is enter channel, time and length (CTL) andvalidity period step812 for the supplemental information associated with an advertisement. The channel, time and length are self explanatory. The validity period is necessary, because the encoding and decoding algorithms have a step in which a scramble occurs. To guarantee that the I code associated with an advertisement will be able to be used, two overlapping scrambling time periods are used. For example suppose that a first scrambling method is constant for two months from January 1st to February 28th and then changes every succeeding two month period. An overlapping and skewed second scrambling method would be constant from February 1st to March 31st and then change every succeeding two month period. For an advertisement that would run from January 20th to February 10, the first scrambling method would be used for encoding and decoding; however, for an advertisement that would run from February 25th through March 9th, then the second scrambling method would be used. Thus, the validity period input at the beginning of the encoding process specifies which scrambling method to use.

The next step is the lookup assignedchannel number step816, which substitutes an assigned channel number822 for eachchannel818 of theinput CTL814. Often, for example for network broadcast channels, such aschannel 2, the assigned channel number is the same; however, for a cable channel such as HBO a channel number is assigned and is looked up in a cable assigned channel table820, which would essentially be the same as the first two columns of the table ofFIG. 28. Next, the lookup priority of channel, time and length in priority vector tables step824 performs a lookup in priority vector channel (C) table826 and priority vector time/length (TL) table830 using the indices of channel and time/length, respectively, to produce the vector C_p, TL_p832. The use of a combined time/length (TL) table to set priorities recognizes that there may be some relationship between these combinations for additional information. For example, at 2 AM movie previews could be broadcast and be somewhat longer than other information, but very popular. Alternately, it is possible to have separate priority tables for time and length.

The channel priority table is ordered so that in general the least frequently used channels for I codes have high priority numbers and the most frequently used channels for I codes have a low priority number, which contributes to deriving shorter I codes for the most popular supplemental information broadcasts. Note that because the information broadcasts are least expensive if done on off hours on seldom used channels, that it is likely that the channels with the lowest priority numbers for G codes may have the highest priority numbers for I codes. For example, a short G code may be forchannel 2 on Monday at 8 p.m. for 1 hour during prime time, while a short I code may be for channel 17 at 4 a.m. for 5 minutes. The typical information broadcast may be only about 3 to 5 minutes compared to the typical 30 to 60 minute program. An example of the data that is in the priority vector C table826 follows.

	channel

	4	7	2	3	5	6	11	13 . . .

priority	0	1	2	3	4	5	6	7 . . .

The priority of the start times and length of the information broadcasts corresponding to I codes are conceivably the inverse of the priorities of the G codes, because G codes are arranged so that prime time programs will have the shortest G codes. In the case of I codes, they would be arranged to have the shortest codes when the broadcast time is least expensive, which is certainly not prime time. Thus, if the G codes are encoded for prime time, then the I codes are encoded for nonprime time or the inverse of prime time. The priority for time and length could be arranged in a matrix that would assign a priority to each combination of start times and information broadcast lengths so that more popular combinations of start time and length would have a low priority number and less popular combinations would have a high priority number, which also contributes to deriving shorter codes for the most popular supplemental information broadcasts. For example, a partial priority vector T/L table830 might appear as follows.

Priority TL Table

TIME

Length (hrs)	2:30 am	3:00 am	3:30 am	4:00 am . . .

.1	8	4	7	10 . . .
.2	12	15	13	18 . . .
.3	20	19	17	30 . . .

Alternately as indicated before, separate priority tables could be constructed for start times and broadcast length with the lowest priority numbers given to the most likely start times for I code broadcasts and most likely broadcast lengths. Suppose the channel, time and length (CTL)814 data ischannel 5, 3:00 am and 0.3 hours in length, then the C_p, TL_p832 for the above example would be419. The next step is the convert C_p, TL_pto binary numbers and concatenate them into one binary number step834, resulting in the data word . . . TL₂TL₁. . . C₂C₁836. For the example given above, converting the . . . TL₂TL₁. . . C₂C₁836 word to binary would yield the two binary numbers: . . . 0010011, . . . 0100. The number of binary bits to use in each conversion is determined by the number of combinations involved. This could vary depending on the implementation; however one preferred embodiment would use eight bits for C_p, denoted as C₈C₇C₆C₅C₄C₃C₂C₁, which would provide for 256 channels, and fourteen bits for TL_p, denoted as TL₁₄. . . TL₃TL₂TL₁, which would provide for start times spaced every 5 minutes over 24 hours and information broadcasts in increments of 5 minute lengths for information broadcasts up to 3 hours in length. This requires about 288*(36+20)=16, 128 combinations, which are provided by the 2**14=16, 384 binary combinations. Altogether there are 8+14=22 bits of information TL₁₄. . . TL₂TL₁C₈. . . C₂C₁. For the above example padding each number with zeros and then concatenating them would yield the 22 bit binary number: 0000000001001100000100.

The next step is to usebit hierarchy key840, which can be stored in read only memory64 to perform the reorder bits of binary number according to bit hierarchykey step838. Abit hierarchy key840 can be any ordering of the . . . TL₂TL₁. . . C₂C₁836 bits and in general will be selected so that information broadcasts most likely to be the subject of timer preprogramming would have a lowvalue I code854, which would minimize keystrokes. The ordering of the bit hierarchy key can be determined by the differential probabilities of the various bit combinations as previously discussed. The details of deriving abit hierarchy key840 were described relative tobit hierarchy key120 and the same method can be used forbit hierarchy key840. For example, the bit hierarchy key might be:

TL8	C3	. . .	TL10	C2	TL1	C1
22	21	. . .	4	3	2	1

The next step is the insert validityperiod code step841. Thevalidity period code845 must be at least one bit, but could be more, and is set by the selectscramble function step844, which is dependent on the validity period of the information broadcast, as explained above. The selectscramble function step844 also selects an associated scramble method, which provides security for the resultingI code854. Thevalidity period code845 is inserted into the I code and is used to designate the scramble method to be used during decoding.

FIG. 33 is an illustration of the problem addressed by thevalidity period code845. Suppose a particular scramble method is constant during time span930 and then changes at the start of time span932, and each succeeding two month time span. For most advertisements, theI code854 would have to be constant for a period of time, for example a week for I codes in weekly publications. If the time spans930 and932 are two months as shown inFIG. 33, then a one week validity period might overlap both time spans930 and932, which would mean that the scramble method would change during the validity period. To compensate for this, a skewed and overlapping set of time spans for a second scramble method is provided. For example, time span934 and time span936, which are skewed from time span930 and time span932 by one month. The scramble time spans930,932 and so on, can be designated by a validity period code “0”. The offset scramble time spans934,936 and so on can be designated by a “1”. Suppose there is avalidity period938 for one week for aI code854, then the scramble method selected would be those valid during time span930, time span932 and so on and the validity period code for that validity period would be set to “0”, as shown byvalidity period codes944. The validity period code would also be “0” for thevalidity period942. However, forvalidity period940, the validity period code would be set to “1”, because that corresponds to the scramble method that is constant during time span934.

Note that if only two skewed time spans are used and the validity period code is placed in the least significant bit of the binary word instep841, and the least significant digit is not scrambled in step846, then once the I code is derived it is possible when decoding the I code to determine the validity period code merely by inspecting whether the I code is even or odd.

The next step is the combine groups of bits and convert each group into decimal numbers and concatenate into onedecimal number step842. For example, after reordering according to the bit hierarchy key and insertion of the validity period code (suppose its “1” in this example, because the validity period is February 25th to March 9th, for which a validity period code of 1 would be used as shown inFIG. 33), the code may be 00000000110000000010011, which could be grouped as 0000000011, 0000000010011. If these groups of binary bits are converted to decimal as 3,19 and concatenated into one decimal number, then the resulting decimal number is 319. The next encoding step is the scramble decimal number step846, which scrambles the decimal number according toscramble function844 that is dependent on thevalidity period848, such as February 25th through March 9th, for the information broadcast and provides a security feature for the codes. After the scramble decimal number step846, the decimal code I_n. . . I₂I₁850 may, for example, be 139. The last step is to insert a zero (0) for thefirst digit step852, so that the code is distinguishable to theinstant programmer300 as aI code854. The result for the example would be 0139. These encoded codes are then included in an advertisement, for example as in theI code652 ofFIGS. 29aand29b.

FIG. 32 is aflowchart860 of the method for decoding an I code into channel, time and length, which is step714 ofFIG. 30. Note thatstep711 ofFIG. 30 has already determined that the entered code is an I code versus a G code, because the first digit is a zero. First, the I code0I_n. . .862 is entered. Then the zero is deleted in the remove leading zerostep864 to obtain I_n. . . I₂I₁865.

Next, it is necessary to invert the scramble method ofsteps844 and846 ofFIG. 31. The first step is the extract validity period code step866. Thevalidity period code867 indicates, which of two skewed in time scrambling methods to use. Thescramble method878 selected by scramble function870 also depends on clock876, which is implemented bymicrocomputer380 inFIGS. 21 and 22. The clock876 has the current time, day, month and year. The selectedscramble method878 is used in the invert scramble ofI code step880. For the example given above, the output ofstep880 would be:319. The next step is the convert groups of decimal numbers into groups of binary numbers and concatenate binary groups into onebinary number step884, which is the inverse ofstep842 ofFIG. 31 and for the above example would result in the binary code: 00000000110000000010011. Then the validity period code would be deleted instep885, which invertsstep841 ofFIG. 31, the result being: 0000000011000000001001. Then thebit hierarchy key888 is used in the reorder bits of binary number according to bit hierarchykey step886, which invertsstep838 ofFIG. 31 to obtain 0000000001001100000100 for the above example, which is . . . TL₂TL₁. . . C₂C₁. . . D₂D₁882 corresponding to836 ofFIG. 31. The next step is to group bits to form two binary numbers TL_b, C_band convert to decimal numbers step890 resulting in C_p,TL_p892, which for the example above would be: 4,19, and which are priority vectors for channel and time/length, which in turn are used to lookup channel, time andlength904 in priority vector channel (C) table898 and priority vector time/length (TL) table902, respectively. For the above example, this would result in looking upchannel 5 and time/length of 3 a.m./0.3 hours.

The lookup local channel number step906 looks up the local channel912 given the assignedchannel number908, in the assigned/local channel table910, which is setup by the user via theCH key322, as explained above.

Another preferred method of encoding and decoding the I codes is the following, which is similar to the foregoing except where noted. Channel, time and length priority tables would be used to encode and decode the I codes, as described before. The key difference is that the bit hierarchy is no longer defined inbase2 arithmetic. Rather it is defined in a generalized base arithmetic as shown in the following table:

Validity Per.	#

No. of Digits	Ch	Time	Len	CodeBits	Combination	Order

1	1	3	2	0*	6	TTL
2	16	3	2	0*	96	CCCC
3	16	30	2	0*	960	TTTT
4	32	75	4	0*	9600	TCTL
5	64	90	8	1	92160	TLCS
6	64	360	20	1	921600	LLTT
7	128	720	50	1	9216000	LLTC
8	129	1440	250	1	92160000	LLLT
*validity period code bit assumed to be equal to zero.
C = channel bit
T = start time bit
L = length bit
S = validity period code bit

For example, if only one digit is used, there are one channel (1C), three start times (3T's) and two length (2 L's), i.e. 6 combinations. It is assumed that the I code before appending the leading zero has only one digit and that in this case both the encoding and decoding methods understand that the validity period code is “0”. With two digits, there are inaddition 16 times more C's (i.e. 16 C's), so that there are now 3×2×16=96 combinations in the first 2 digits. With three digits, there are now 10 times more T's so that there are now 3 (from digit 1)×10 (from digit 3)=30 T's. The total number of combinations equals 3×2×16×10=2×30×16=960 in the first 3 digits. With four digits, there are now 2 more time C's,2 more times L's and 2.5 times more T's, so that the number of combinations increases by 2×2×2.5=10 times. There are now 9600 combinations in the first 4 digits. With five digits, there are 2 more times C, 1.2 more times T's, 2 more times L's and an extra bit for scrambling so that there are now 2×1.2×2×2=9.6 times more combinations =9600×9.6=92160 combinations. One way to obtain a non-integral number of times such as 1.2 or 1.25 or 2.5 times is essentially by providing a table which defines the range of values for each number of digits that corresponds to the above table.

Thus, steps834 and838 inFIG. 31 would be implemented in this preferred embodiment in the manner indicated above and there are other subtle changes such as the handling of the assumed validity period code as indicated above for cases with four or fewer digits in the I code not counting the leading zero. I code decoding would be the reverse of the encoding method.

An example of the encoding to reduce the number of digits in the I code is shown below. In this example, suppose one variable is represented by the digits DA₁, DA₂and ranges from 0 to 24, where DA₁ranges from 0 to 2 and. DA₂ranges from 0 to 9 and another variable DB ranges from 0 to 3, so the total number of values being encoded is 25*4=100. It is possible to represent the first variable by two digits and the second variable by one digit; however, that is inefficient, because it would require the listing of three digits. The number of combinations of the two variables is only 25*4=100, so it is possible to represent the combination of the variables in only 2 binary coded decimals. The desire is to encode the DA₁, DA₂and DB, which are 3 digits into two binary coded decimal digits d₁and d₂, where the permissible values of d₁and d₂range only between 0 and 9.

This is possible as shown in the table below, where the encoding algorithm is the following:

• • A3*2¹+A2*2⁰=DA₂
  • A1=DA₁unless DB≧2& DA₂=2,
  • then A1=DA₁+5
  • B2*2¹+B1*2⁰=DB unless DB≧2& DA₂=2,
  • then B2*2¹+B1*2⁰=DB−2

The resulting binary coded decimals are denoted d₂, which equals A3*2³+A2*2²+B2*2¹+B1*2⁰and ranges from 0 to 9, and d₁, which ranges from 0 to 9 and equals A1.

Once encoded, the binary coded decimals d₂and d₁can be decoded by first representing them in binary form and then deriving DA₂, DA₁and DB as follows:

		d2	d1	Decimal Encoding

DA1, DA2	DB	A3	A2	B2	B1	A1	d2	d1

0	0	0	0	0	0	0	0	0
1	0	0	0	0	0	1	0	1
2	0	0	0	0	0	2	0	2
3	0	0	0	0	0	3	0	3
4	0	0	0	0	0	4	0	4
5	0	0	0	0	0	5	0	5
6	0	0	0	0	0	6	0	6
1	0	0	0	0	0	7	0	7
8	0	0	0	0	0	8	0	8
9	0	0	0	0	0	9	0	9
10	0	0	1	0	0	0	4	0
11	0	0	1	0	0	1	4	1
12	0	0	1	0	0	2	4	2
13	0	0	1	0	0	3	4	3
14	0	0	1	0	0	4	4	4
15	0	0	1	0	0	5	4	5
16	0	0	1	0	0	6	4	6
17	0	0	1	0	0	7	4	7
18	0	0	1	0	0	8	4	8
19	0	0	1	0	0	9	4	9
20	0	1	0	0	0	0	0	8
21	0	1	0	0	0	1	8	1
22	0	1	0	0	0	2	8	2
23	0	1	0	0	0	3	8	3
24	0	1	0	0	0	4	8	4
0	1	0	0	0	1	0	1	0
1	1	0	0	0	1	1	1	1
2	1	0	0	0	1	2	1	2
3	1	0	0	0	1	3	1	3
4	1	0	0	0	1	4	1	4
5	1	0	0	0	1	5	1	5
6	1	0	0	0	1	6	1	6
7	1	0	0	0	1	7	1	7
8	1	0	0	0	1	8	1	8
9	1	0	0	0	1	9	1	9
10	1	0	1	0	1	0	5	0
11	1	0	1	0	1	1	5	1
12	1	0	1	0	1	2	5	2
13	1	0	1	0	1	3	5	3
14	1	0	1	0	1	4	5	4
15	1	0	1	0	1	5	5	5
16	1	0	1	0	1	6	5	6
17	1	0	1	0	1	7	5	7
18	1	0	1	0	1	8	5	8
19	1	0	1	0	1	9	5	9
20	1	1	0	0	1	0	9	0
21	1	1	0	0	1	1	9	1
22	1	1	0	0	1	2	9	2
23	1	1	0	0	1	3	9	3
24	1	1	0	0	1	4	9	4
0	2	0	0	1	0	0	2	0
1	2	0	0	1	0	1	2	1
2	2	0	0	1	0	2	2	2
3	2	0	0	1	0	3	2	3
4	2	0	0	1	0	4	2	4
5	2	0	0	1	0	5	2	5
6	2	0	0	1	0	6	2	6
7	2	0	0	1	0	7	2	7
8	2	0	0	1	0	8	2	8
9	2	0	0	1	0	9	2	9
10	2	0	1	1	0	0	6	0
11	2	0	1	1	0	1	6	1
12	2	0	1	1	0	2	6	2
13	2	0	1	1	0	3	6	3
14	2	0	1	1	0	4	6	4
15	2	0	1	1	0	5	6	5
16	2	0	1	1	0	6	6	6
17	2	0	1	1	0	7	6	7
18	2	0	1	1	0	8	6	8
19	2	0	1	1	0	9	6	9
20	2	1	0	0	0	5	8	5
21	2	1	0	0	0	6	8	6
22	2	1	0	0	0	7	8	7
23	2	1	0	0	0	8	8	8
24	2	1	0	0	0	9	8	9
0	3	0	0	1	1	0	3	0
1	3	0	0	1	1	1	3	1
2	3	0	0	1	1	2	3	2
3	3	0	0	1	1	3	3	3
4	3	0	0	1	1	4	3	4
5	3	0	0	1	1	5	3	5
6	3	0	0	1	1	6	3	6
7	3	0	0	1	1	7	3	7
8	3	0	0	1	1	8	3	8
9	3	0	0	1	1	9	3	9
10	3	0	1	1	1	0	7	0
11	3	0	1	1	1	1	7	1
12	3	0	1	1	1	2	7	2
13	3	0	1	1	1	3	7	3
14	3	0	1	1	1	4	7	4
15	3	0	1	1	1	5	7	5
16	3	0	1	1	1	6	7	6
17	3	0	1	1	1	7	7	7
18	3	0	1	1	1	8	7	8
19	3	0	1	1	1	9	7	9
20	3	1	0	0	1	5	9	5
21	3	1	0	0	1	6	9	6
22	3	1	0	0	1	7	9	7
23	3	1	0	0	1	8	9	8
24	3	1	0	0	1	9	9	9
DA2= A3 * 21+ A2 * 20
DA1= A1 unless A3 = 1 and A1 ≧ 5, then DA1 = A1 − 5
DB = B2 * 21+ B1 * 20unless A1 ≧ 5, then DB = (B2 + 1) * 21+ B1 * 20

Note if the weights of the A3, A2, B2 and B1 bits are 20, 10, 50, and 25, that the weighted sum of the bits plus the A1 digit sequence properly from 0 through 99, for the example table above, except for what should be theweighted sums 70 through 74 and 95 through 99 combinations, which have instead a weighted sum of 25 through 29 and 50 through 54, respectively. This results in the logic above that recognizes that DA₁never exceeds thevalue 4. This is used to advantage to keep d₂within a binary coded decimal value of 0 to 9 by replacing what should be a 1 in B2 with a zero and adding 5 to A1, thereby resulting in the difference of 5−50=−45 between the expected 70 and resulting 25 and the expected 95 and resulting 50, for example. As shown in the logic above, simple tests determine the proper encoding and decoding.

In summary the apparatus and methods described enable a user to selectively record additional information associated with a printed or broadcast advertisement, which would be broadcast on a television channel at a later time. The user enters the digital code (I code) associated with an advertisement into a unit with a decoding means which automatically converts the I code into CTL (channel, time and length). The unit within a twenty four hour period activates a VCR to record information on the television channel at the right start time for the proper length of time. The additional information could be broadcast on a television channel early in the morning, for example, between midnight and six o'clock in the morning, when the cost of broadcast time is low and it is economical to broadcast detailed information or advertisements of many items, such as automobiles, real estate and movie previews. The user can then view this information at his/her leisure. This invention will allow the user an unprecedented capability to control access to desired information without having to be continually glued to the television. It will also provide a new and cost effective means for advertisers to explain their goods and services. It is thought that the apparatus and method for using compressed codes for scheduling broadcast information recording of the present invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts thereof without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred or exemplary embodiment thereof.

Claims (4)

1. An apparatus for using compressed codes for information broadcast recording that comprises:

an interface that receives compressed codes each having at least one digit and each representative of, and compressed in length from, the combination of of channel, time-of-day and length commands for an information broadcast and each having an indicator digit indicating that the compressed code does not include or represent a date command;

a decoder that decodes a compressed code having at least one digit and an indicator digit indicating that the compressed code does not include or represent a date command into channel, time-of-day and length commands; and

a controller configured to have recorder start recording according to the time-of-day command during the twenty-four hour period following receipt of the compressed code.

2. The apparatus for using compressed codes ofclaim 1 wherein each compressed code: has a length less than the length of the concatenation of said set of channel, time-of-day and length commands.

3. The apparatus for using compressed codes ofclaim 1 wherein each compressed code: comprises one or more alphanumeric characters.

4. A method for using compressed codes for information broadcast recording that comprises:

receiving compressed codes, each having at least one digit and each representative of, and compressed in length from, the combination of channel, time-of-day and length commands for an information broadcast and each having an indicator digit indicating that the compressed code does not include or represent a date command;

decoding a compressed code having at least one digit and an indicator digit indicating that the compressed code does not include or represent a date command into channel, time-of-day and length commands; and

turning the recording function of a recorder on according to the time-of-day command during the twenty-four hour period following receipt of the compressed code.

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